Showing papers in "American Journal of Cardiology in 1988"
TL;DR: The addition of enalapril to conventional therapy in patients with severe congestive heart failure can reduce mortality and improve symptoms, and the effect seems to be due to a reduction in death from progression of heart failure.
Abstract: To evaluate the influence of the angiotensin-converting enzyme inhibitor, enalapril (2.5 to 40 mg/day), on the prognosis of severe congestive heart failure, defined as New York Heart Association functional class IV, a double-blind study was undertaken in which 253 patients were randomized to receive either placebo (n = 126) or enalapril (n = 127) in addition to conventional treatment, including vasodilators. Follow-up averaged 188 days (range 1 day to 20 months). The reduction in crude mortality within 6 months (primary objective) was 40% in the enalapril-treated group (from 44 to 26%, p = 0.002) and within 1 year 31% (p = 0.001). By the end of the study, 68 subjects in the placebo group and 50 in the enalapril group had died--a reduction of 27% (p = 0.003). The entire reduction in total mortality (50%) was found in patients dying from progressive heart failure, whereas no difference was seen in the incidence of sudden cardiac death. There was a significant improvement in New York Heart Association classification in the enalapril group, together with a reduction in heart size and a reduced requirement for other heart failure medication. It is concluded that the addition of enalapril to conventional therapy in patients with severe congestive heart failure can reduce mortality and improve symptoms. The effect seems to be due to a reduction in death from progression of heart failure.
4,328 citations
TL;DR: The frequency characteristics of HR fluctuations in patients with severe CHF are consistent with abnormal baroreflex responsiveness to physiologic stimuli, and suggest that there is diminished vagal, but relatively preserved sympathetic, modulation of HR.
Abstract: Neurohumoral modulation of cardiovascular function is an important component of the hemodynamic alterations in patients with chronic congestive heart failure (CHF). Analysis of heart rate (HR) variability is a noninvasive means of investigating the autonomic control of the heart. The variability of HR and respiratory signals, both derived from ambulatory electrocardiographic recordings, were analyzed with power spectral analysis to evaluate autonomic control in 25 patients with chronic stable CHF (class III or IV) and 21 normal control subjects. In the patients with CHF, HR spectral power was markedly reduced (p less than 0.0001) at all frequencies examined (0.01 to 1.0 Hz, period 1 to 100 seconds) and virtually absent at frequencies greater than 0.04 Hz. Heart rate fluctuations at very low frequencies (0.01 to 0.04 Hz) less effectively differentiated CHF patients from control subjects, due to discrete (about 65 seconds, 0.015 Hz) oscillation in HR, which was associated with a similar pattern in respiratory activity in many of the patients with CHF. These findings demonstrate a marked derangement of HR modulation in patients with severe CHF. The frequency characteristics of HR fluctuations in these patients are consistent with abnormal baroreflex responsiveness to physiologic stimuli, and suggest that there is diminished vagal, but relatively preserved sympathetic, modulation of HR.
743 citations
555 citations
TL;DR: D markedly reduced fibrinolytic activity during the early morning hours related to increased plasminogen activator inhibition is reported.
Abstract: Natural inhibitors of endogenous fibrinolysis may displace the hemostatic equilibrium toward thrombosis and favor events such as acute myocardial infarction, sudden cardiac death and stroke, where a thrombotic process is known to occur.1,2 The clinical incidence of these syndromes shows a circadian distribution with highest frequency in the morning.3,5 These observations prompted us to investigate possible circadian changes of blood fibrinolytic activity in normal subjects. Two major components of the fibrinolytic system, tissue-type plasminogen activator (t-PA) and its fast-acting inhibitor (PAI), were measured with specific assays. This study reports markedly reduced fibrinolytic activity during the early morning hours related to increased plasminogen activator inhibition.
445 citations
TL;DR: Analysis of 24-hour electrocardiograms showed that for the low HR variability group compared with the high: (1) the daytime and nighttime average HR was faster; (2) the difference between daylight and nighttime HR was less; (3) the proportion of differences greater than 50 ms between successive N-N intervals was smaller; and the number of HR "spikes" per day was less.
Abstract: A high degree of heart rate (HR) variability is found in persons with normal hearts, whereas low HR variability can be found in patients with severe coronary artery disease, congestive heart failure and diabetic neuropathy. Two weeks after acute myocardial infarction, low HR variability predicted reduced long-term survival even after adjusting for clinical risk indicators, left ventricular ejection fraction, HR and ventricular arrhythmias. The present study elucidated the causes of differences in HR and HR variability between patients with low and high HR variability. In a matched-pair study, 10 patients with low HR variability (24-hour standard deviation of N-N intervals less than 50 ms) were randomly selected. For each of these 10 patients, a control patient with high HR variability (24-hour standard deviation of N-N intervals greater than or equal to 100 ms), matched for age, left ventricular ejection fraction and rales in the coronary care unit was selected. Patients who were taking either digitalis or beta-adrenergic blocking drugs were excluded. Analysis of 24-hour electrocardiograms showed that for the low HR variability group compared with the high: (1) the daytime and nighttime average HR was faster; (2) the difference between daytime and nighttime HR was less; (3) the proportion of differences greater than 50 ms between successive N-N intervals was smaller; and (4) the number of HR "spikes" per day (increase in HR greater than or equal to 10 beats/min, lasting from 3 to 15 minutes) was less.(ABSTRACT TRUNCATED AT 250 WORDS)
392 citations
TL;DR: There is a need for standardization of lead selection practice for QT measurement if measurements are confined to one or a few leads, anteroseptal leads provide the closest approximation to QTmax.
Abstract: The influence of lead selection on QT estimation in the 12-lead electrocardiogram was assessed in 63 patients (21 control subjects, 21 with anterior myocardial infarction, 21 with inferior myocardial infarction). QT estimates varied between leads. The variation was greater in patients with myocardial infarction than in control subjects (mean dispersion of QT: control subjects, 48 ± 18 ms [± standard deviation]; anterior myocardial infarction, 70 ± 30 ms; inferior myocardial infarction, 73 ± 32 ms). The maximum QT in any lead (QTmax) was determined and the deviation of each lead from this maximum value calculated. In all 3 groups, anteroseptal leads (V2 or V3) provided the closest approximation to QTmax. Interlead variability was found to be mainly due to variation in timing of the end of the T wave, rather than the onset of the QRS complex. The variability due to leads was considerably greater than the variability due to cycles, observers or measurement error. Implementation of a variety of current lead selection practices resulted in widely divergent estimates of QT interval. It is concluded that there is a need for standardization of lead selection practice for QT measurement. If measurements are confined to one or a few leads, anteroseptal leads provide the closest approximation to QTmax.
344 citations
TL;DR: Lovastatin effectively diminishes endogenous cholesterol synthesis providing useful therapeutic properties for patients with hypercholesterolemia.
Abstract: Cholesterol is a 27-carbon steroid that is an essential component of the cell membrane, the immediate precursor of steroid hormones, the substrate for the formation of bile acids, and is required for the assembly of very low density lipoprotein in the liver. Because as much as two-thirds of total body cholesterol in patients is of endogenous origin, an effective means to control cholesterogenesis may occur by inhibition of its biosynthesis. Cholesterol is biosynthesized in a series of more than 25 separate enzymatic reactions that initially involve the formation of 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA). Early attempts to pharmacologically block cholesterol synthesis focused only on steps later in the biosynthetic pathway and resulted in compounds with unacceptable toxicity. Recent research had identified that HMG CoA reductase is a key rate-limiting enzyme in this pathway and is responsible for the conversion of HMG CoA to mevalonate. Additional research with fungal metabolites identified a series of compounds with potent inhibiting properties for this target enzyme, from which lovastatin was selected for clinical development. A reduction in cholesterol synthesis by lovastatin has been subsequently confirmed in cell culture, animal studies and in humans. A resultant decrease in circulating total and low-density lipoprotein (LDL) cholesterol has also been demonstrated in animals and humans. Because hepatic LDL receptors are the major mechanism of LDL clearance from the circulation, further animal research has confirmed that these declines in cholesterol are accompanied by an increase in hepatic LDL receptor activity. Lovastatin effectively diminishes endogenous cholesterol synthesis providing useful therapeutic properties for patients with hypercholesterolemia.
343 citations
TL;DR: The good adverse-effect profile of lovastatin is supported both by a substantial body of data in patients treated for over 2 years in clinical trials, and by experience in clinical use with a large number of patients since the drug has been available for prescription.
Abstract: The efficacy of lovastatin, a potent inhibitor of HMG CoA reductase, has been established by numerous studies. At doses of 40 mg administered twice daily, lovastatin produces a mean reduction in total plasma cholesterol of 33%, attributable to a reduction in low-density lipoprotein cholesterol of 41%. The drug also produces a mean increase in high-density lipoprotein cholesterol of 9%, and a reduction in the high- and low-density lipoprotein cholesterol ratio of 44%. The serious reported adverse effects of lovastatin are myopathy (0.5%) and asymptomatic but marked and persistent increases in transaminases (1.9%). Both are reversible when therapy is discontinued. Myopathy has occurred mainly in patients with complicated histories who were receiving concomitant therapy with immunosuppressive drugs, gemfibrozil or niacin. In an ongoing long-term safety study, 744 patients have received lovastatin for an average duration of 2.5 years up to March 1988. Fifteen patients (2.0%) have been withdrawn because of drug-attributable adverse events: raised transaminases (9), skin rash (2), gastrointestinal symptoms (2), myopathy (1) and insomnia (1). No effect of the drug on the human lens has been observed up to the date mentioned above. Lovastatin has been available in the United States since September 1987. By March 1988, the drug had been prescribed for approximately 250,000 patients. This clinical experience has confirmed the tolerability observed in clinical trials. The good adverse-effect profile of lovastatin is thus now supported both by a substantial body of data in patients treated for over 2 years in clinical trials, and by experience in clinical use with a large number of patients since the drug has been available for prescription.
332 citations
TL;DR: Coronary dominance, not ostial shape, was useful in separating the clinically significant from the clinically insignificant anomalies.
Abstract: Anomalous origin of either the left main coronary artery (LMCA) or right coronary artery (RCA) from the aorta with subsequent coursing between the aorta and pulmonary trunk is a rare and sometimes fatal coronary artery anomaly. Thirty-two cases of these anomalies were reviewed, with particular attention to the exact location and shape of the anomalistically positioned ostium and coronary dominance. The LMCA (7 cases) arose either from behind the right coronary sinus (6 cases) or as a single ostium with the RCA straddling the right-left commissure and right coronary sinus (1 case). In 5 of the 7 cases, the anomaly was fatal. In 6 cases of anomalous origin of the LMCA, the RCA was dominant and in 4 the anomaly was fatal. In only 1 case of anomalous origin of the LMCA was the left circumflex coronary artery dominant, and in this case the anomaly also was fatal. The RCA (25 cases) arose either from behind the left coronary sinus (8 cases), above the left coronary sinus (5 cases), from above the right-left commissure (10 cases) or as a single ostium with the LMCA above the right-left commissure and left coronary sinus (2 cases). In 8 of these 25 cases the anomaly was fatal. In 7 cases of anomalous origin of the RCA, the left circumflex coronary artery was dominant and in no case was the anomaly clinically significant. In 1 case, both the RCA and left circumflex coronary artery were hypoplastic and the anomaly was fatal. Coronary dominance, not ostial shape, was useful in separating the clinically significant from the clinically insignificant anomalies.
311 citations
TL;DR: A 2-part prospective study was performed to evaluate the clinical outcome of patients with hemodynamically confirmed asymptomatic valvular aortic stenosis and found both groups of patients in phase 2 had similar Doppler gradients and clinical and auscultatory evidence of moderate to severe AS at baseline.
Abstract: A 2-part prospective study was performed to evaluate the clinical outcome of patients with hemodynamically confirmed asymptomatic valvular aortic stenosis (AS). During phase 1, linear regression analysis showed continuous wave Doppler to be highly accurate in predicting catheterization measured peak systolic aortic valve pressure gradients in 101 consecutive patients aged 36 to 83 years (mean 65 +/- 8) with symptomatic AS. During phase 2, 90 additional patients (51 asymptomatic and 39 symptomatic) with Doppler-derived peak systolic aortic valve gradients greater than or equal to 50 mm Hg (range 50 to 132 [mean 68 +/- 19]) were followed for 1 to 45 months. Both groups of patients in phase 2 had similar Doppler gradients and clinical and auscultatory evidence of moderate to severe AS at baseline. Asymptomatic patients were younger (p = 0.01), had higher ejection fractions (p = 0.001) and were less likely to have an electrocardiographic strain pattern (p = 0.01) and left atrial enlargement (p = 0.02). End-diastolic wall thickness, left ventricular cross-sectional myocardial area and estimated left ventricular mass were 18% (p = 0.0001), 20% (p = 0.0008), and 29% (p = 0.002) greater in symptomatic patients. During 17 +/- 9 months of follow-up, 21 asymptomatic patients (41%) became symptomatic. Dyspnea was the most common initial complaint, occurring 2.5 and 4.8 times more often than angina and syncope, respectively. Compared with the 39 symptomatic patients, the 51 asymptomatic patients had a lower cumulative life table incidence of death from any cause (p = 0.002), and from cardiac causes (p = 0.0001) including sudden death (p = 0.013).(ABSTRACT TRUNCATED AT 250 WORDS)
281 citations
TL;DR: Gender had no independent predictive value when variables that included age, congestive heart failure in the hospital, history of congestive failure, prior AMI and diabetes mellitus were considered, and when age stratification was performed, the significant difference of in-hospital mortality between genders was no longer present.
Abstract: The contention that mortality after acute myocardial infarction (AMI) is increased in women compared with men has been controversial, with findings in a recent multicenter study suggesting that gender plays an important prognostic role. To assess whether or not early and late mortality after AMI is greater in women, 2,089 patients (1,551 men, 538 women) were followed for 1 year after AMI. In the hospital, women had an increased mortality compared to men (17.5 vs 12.3%, p less than 0.003) and were on average 7 years older, whereas after hospital discharge and up to 1 year no difference in mortality was observed. Multivariate analyses of historical, clinical and laboratory features demonstrated that gender had no independent predictive value when variables that included age, congestive heart failure in the hospital, history of congestive failure, prior AMI and diabetes mellitus were considered. Moreover, when age stratification was performed, the significant difference of in-hospital mortality between genders was no longer present. Causes of death in the hospital and during 1 year after hospital discharge were similar between men and women, whether or not age stratification was performed. Several baseline clinical characteristics were different between men and women; a history of systemic hypertension and congestive heart failure occurred more frequently in women and previous AMI and smoking occurred more commonly in men. Also, the value of several other important prognostic indicators after AMI, such as the ejection fraction, was found to differ between men and women.(ABSTRACT TRUNCATED AT 250 WORDS)
TL;DR: It is demonstrated that ejection fraction has the most profound effect on survival calculated from maximal oxygen consumption and norepinephrine concentration, but that each of the variables provides additional independent prognostic information when added to survival estimated from any of the other variables.
Abstract: The interaction of physiologic variables that appear to be predictive of prognosis in patients with severe congestive heart failure was examined in a series of 139 patients referred to a heart failure service. Left ventricular ejection fraction, peak oxygen consumption during a progressive maximal exercise test and resting plasma norepinephrine concentration were identified as the strongest univariate predictors of prognosis. Examination of their interaction was accomplished by stratifying each variable into quartiles and then pooling quartiles for bivariate analysis. The data demonstrate that ejection fraction has the most profound effect on survival calculated from maximal oxygen consumption and norepinephrine concentration, but that each of the variables provides additional independent prognostic information when added to survival estimated from any of the other variables. Therefore, ventricular function, exercise tolerance and sympathetic nervous system activation appear to provide independent insight into the prognosis of patients with heart failure.
TL;DR: In this paper, the prognostic value of heart rate variability in patients without recent myocardial infarction and its correlation with other clinical and angiographic data have not previously been reported.
Abstract: Decreased heart rate (HR) variability is associated with increased mortality after myocardial infarction, but the prognostic value of HR variability in patients without recent myocardial infarction and its correlation with other clinical and angiographic data have not previously been reported. In the present study, detailed clinical assessments and 24-hour ambulatory electrocardiograms were performed prospectively on 100 patients undergoing elective coronary angiography. HR variability was inversely correlated with HR (r = −0.38, p = 0.0001), diabetes mellitus (r = −0.22, p = 0.025) and digoxin use (r = −0.29, p = 0.004), but not with left ventricular ejection fraction, extent of coronary artery disease or other clinical, electrocardiographic or angiographic variables. All patients were followed for 1 year. Major clinical events after initial discharge occurred in 10 patients and included 6 deaths and 4 coronary bypass operations. Left ventricular ejection fraction was the only variable that correlated with the occurrence of a clinical event (p = 0.002). Decreased HR variability and ejection fraction were the best predictors of mortality (both p 50 ms (36 vs 2%, p = 0.001). Thus, decreased HR variability is a potent independent predictor of mortality in the 12 months following elective coronary angiography in patients without recent myocardial infarction.
TL;DR: It was concluded that oral digoxin, in doses titrated to produce a serum level of 1.54 to 2.56 nmol/liter, improved quality of life and functional exercise capacity in some patients with CHF in sinus rhythm.
Abstract: Because of conflicting results from studies examining the usefulness of digoxin in congestive heart failure (CHF) patients in sinus rhythm, a cross-over trial was conducted in which 20 patients received 7 weeks of digoxin titrated to a level of 1.54 to 2.56 nmol/liter and 7 weeks of matched placebo. The order of treatments was determined by random allocation and patients, clinicians and research staff were blind to allocation. In patients with deteriorating condition, the treatment period was terminated and outcome measures were obtained. If deterioration occurred during the first period, the patient was crossed over without the code being broken. Seven patients required premature termination of study periods because of increasing symptoms of CHF. All 7 were taking placebo at the time (p = 0.016). Small differences in dyspnea (p = 0.044), walking test score (p = 0.055), clinical assessment of CHF (p = 0.036) and ejection fraction (p = 0.004) favored the digoxin treatment group. Patients with more severe CHF were more likely to benefit from digoxin administration. It was concluded that oral digoxin, in doses titrated to produce a serum level of 1.54 to 2.56 nmol/liter, improved quality of life and functional exercise capacity in some patients with CHF in sinus rhythm.
TL;DR: The in vitro and in vivo evaluation of ultrasound angioscopy is described, a new technique capable of providing dynamic, circumferential images of blood vessels, which is a major diagnostic modality for assessing vascular anatomy.
Abstract: The assessment of the presence and severity of disease in the peripheral and coronary arteries currently requires contrast angiography. Although computed tomography, noninvasive ultrasound imaging and fiberoptic angioscopy may allow visualization of certain portions of the arteries, these techniques have limitations.1–3 Contrast angiography, which yields only long-axis images of the blood vessel lumen, continues to be the major diagnostic modality for assessing vascular anatomy. In this report we describe the in vitro and in vivo evaluation of ultrasound angioscopy, a new technique capable of providing dynamic, circumferential images of blood vessels.
TL;DR: Among patients with good or reduced left ventricular ejection fraction, those with transient ST depression on Holter had a significantly higher cardiac event rate compared with those without it and a similar event rate was found in patients with only silent, only symptomatic and with silent and symptomatic ischemic episodes.
Abstract: This study assessed the prognostic significance of ischemic changes during daily activity as recorded by ambulatory electrocardiographic monitoring in a group of 224 low-risk postinfarction patients. Of the 224 patients studied, 74 (33%) had transient ischemic episodes on Holter monitoring. During the 28 months of follow-up the frequency of cardiac events (cardiac death, reinfarction, hospitalization for unstable angina, balloon angioplasty or coronary bypass surgery) was 51% among those with ischemic episodes on Holter monitoring, compared with 12% in those without such changes (p less than 0.0001). The 74 patients with positive results in their exercise tests and Holter monitoring had a 51% event rate, compared with 20% among the 44 patients with a positive exercise test result but negative Holter results (p less than 0.001). The event rate in those without ischemic changes either on the exercise test or on Holter was only 8.5%. Among patients with good (greater than 40%) or reduced (less than 40%) left ventricular ejection fraction, those with transient ST depression on Holter had a significantly higher cardiac event rate compared with those without it. A similar event rate was found in patients with only silent, only symptomatic and with silent and symptomatic ischemic episodes.
TL;DR: It is concluded that echocardiographic features of myocarditis are polymorphous and nonspecific and can simulate alternatively dilated, hypertrophic, restrictive or "right" ventricular cardiomyopathy, as well as coronary artery disease.
Abstract: This study analyzes morphologic and functional alterations detected by M-mode and 2-dimensional echocardiography in 41 patients with histologically proven myocarditis and different clinical presentations: congestive heart failure (63%), atrioventricular block (17%), chest pain (15%) and supraventricular arrhythmias (5%). Left ventricular dysfunction was common (69%), particularly in patients with congestive heart failure (88%), often without or with minor cavity dilatation. Patients with atrioventricular block or chest pain had usually preserved ventricular function. Right ventricular dysfunction was present in 23%. Additional findings included asynergic ventricular areas (64%), left ventricular "hypertrophy" sometimes reversible (20%), hyperrefractile myocardial areas (23%), ventricular thrombi (15%) and "restrictive" ventricular filling (7%). It is concluded that echocardiographic features of myocarditis are polymorphous and nonspecific. The echocardiographic pattern can simulate alternatively dilated, hypertrophic, restrictive or "right" ventricular cardiomyopathy, as well as coronary artery disease. In an appropriate clinical context, echocardiography can be helpful in the diagnosis of myocarditis and in the selection of patients for endomyocardial biopsy.
TL;DR: The data of both study phases suggest that left ventricular function and clinical outcome after abrupt coronary closure are determined by an interaction between location of the coronary artery obstruction and the amount of collateral flow.
Abstract: Two indexes of collateral blood flow, the ratio of distal coronary occlusion pressure/aortic pressure (DCOP/Pao) and angiographic collateral class were determined during elective angioplasty in 36 patients with normal left ventricular function. The association between collateral indexes and 8 anatomic and clinical variables was assessed. A reduction in luminal diameter by ≥70% predicted angiographically demonstrable collaterals with 100% specificity and 85% sensitivity. Lesion severity (stenosis) correlated with both collateral class and DCOP/Pao: DCOP/Pao = 2.8809 −0.0729 × stenosis +0.00049 × stenosis2. The data suggest a quantitative relation between lesion severity and collateral development beyond a threshold value of 70% stenosis. Left ventricular ejection fraction during ischemia caused by balloon occlusion (EFo) was found to be primarily determined by lesion location; however, collateral flow modified EFo significantly. For mid-left anterior descending and right coronary artery: EFo = 59 + 26 × (DCOP/Pao); for proximal left anterior descending artery: EFo = 24 + 89 × (DCOP/Pao). A model predicting the hemodynamic and clinical consequences of abrupt coronary closure based on lesion location and severity was developed. In the second study phase, this model was tested retrospectively in a different group of 23 patients who experienced coronary occlusion as a complication of angioplasty. The data of both study phases suggest that left ventricular function and clinical outcome after abrupt coronary closure are determined by an interaction between location of the coronary artery obstruction and the amount of collateral flow. Lesion severity and the extent of functional impairment resulting from abrupt coronary closure are inversely related.
TL;DR: Six-month follow-up angiography was performed showing that patients who had a residual stenosis less than 30% after initial atherectomy had a lower restenosis rate than patients with initial residual stenoses greater than 30%.
Abstract: Sixty-one patients with occlusive peripheral vascular disease were treated with transluminal atherectomy, a catheter-mediated technique for removal of atheroma. The technique was performed using 7Fr, 9Fr or 11Fr atherectomy catheters. Mean percent diameter stenosis was reduced from 71 to 23%, by removal of 831 atheromatous specimens in 949 passes of the cutting element through 136 stenoses in 61 patients. All specimens removed were sent for histopathologic examination to determine the components of the atheroma removed, which differed for specimens removed from original vs restenotic lesions. Percent stenosis was reduced to less than 45% in 118 of 136 stenoses (87%). Complications included 1 thrombus, which resolved after intraarterial infusion of streptokinase and 1 probable distal embolization without sequelae. Three angiographic dissections occurred without impairment of blood flow. There were no instances of acute occlusion, vascular spasm or vessel perforation. Six-month follow-up angiography was performed showing that patients who had a residual stenosis 30% (52%); this result demonstrated the importance of performing more complete atherectomy. Transluminal atherectomy appears to be an effective, predictable and safe method for removing occlusive atheromatous deposits from peripheral arteries.
TL;DR: The National Heart, Lung, and Blood Institute initiated the Cardiac Arrhythmia Pilot Study (CAPS) to evaluate the feasibility of suppressing ventricular arrhythmias after acute myocardial infarction and found encainide and flecainide had higher efficacy rates than imipramine, moricizine, or placebo, as first drugs.
Abstract: The National Heart, Lung, and Blood Institute initiated the Cardiac Arrhythmia Pilot Study (CAPS) to evaluate the feasibility of suppressing ventricular arrhythmias after acute myocardial infarction. Ten centers enrolled 502 patients younger than 75 years of age with greater than or equal to 10 ventricular premature complexes (VPC) per hour in a 24-hour electrocardiographic recording and a left ventricular ejection fraction greater than 20%. Patients were enrolled 6 to 60 days after acute myocardial infarction and randomized to 1 of 5 treatment tracks with 2 drugs that included encainide, flecainide, imipramine, moricizine or placebo. During a double-blind drug and dose selection phase, investigators were permitted to change drug or dosage to achieve greater than or equal to 70% suppression in VPC frequency and greater than 90% suppression of runs of VPC with the exception of patients assigned to placebo, who continued receiving it. Patients were followed for a year after randomization. Patients in the 5 treatment arms were similar in age, sex, clinical characteristics, VPC frequency, left ventricular ejection fraction and concomitant drug treatment. As first drugs, encainide and flecainide had higher efficacy rates, 79% and 83%, respectively, than imipramine, 52%, moricizine, 66%, or placebo, 37%. Encainide and flecainide also had high efficacy rates, 68% and 69%, in patients who failed imipramine or moricizine. Encainide, flecainide and moricizine were well tolerated. These 3 drugs had intolerable adverse effect rates of 6% or less, i.e., similar to placebo. More than 70T of the patients who started the follow-up phase on encainide, flecainide or moricizine remained on these drugs to the end of the study.(ABSTRACT TRUNCATED AT 250 WORDS)
TL;DR: The 12-lead electrocardiogram alone, when systematically analyzed, can be used to accurately diagnose the origin of wide complex tachycardias with left bundle branch block pattern VT associated with anterior and inferior myocardial infarction.
Abstract: Four electrocardiographic criteria for ventricular tachycardia (VT) were proposed and evaluated. These included (1) an R wave in V1 or V2 of greater than 30-ms duration; (2) any Q wave in V6; (3) a duration of greater than 60 ms from the onset of the QRS to the nadir of the S wave in V1 or V2 and (4) notching on the downstroke of the S wave in V1 or V2. The data showed that all 4 criteria had high predictive accuracy (96 to 100%) and specificity (94 to 100%). The relatively low sensitivities of the 4 criteria alone (30 to 64%) might limit their efficacy. Grouped criteria, however, could differentiate VT from supraventricular tachycardias with high sensitivity, specificity and predictive accuracy. The amount of tracings having either electrocardiographic criteria (1) or (2) or (3) or (4) was determined. The proposed combined criteria had a sensitivity of 100%, specificity of 89% and a predictive accuracy of 96%. Left axis deviation alone was of no value in distinguishing VT from supraventricular tachycardia. Characteristic patterns were present for left bundle branch block pattern VT associated with anterior and inferior myocardial infarction. In conclusion, the 12-lead electrocardiogram alone, when systematically analyzed, can be used to accurately diagnose the origin of wide complex tachycardias with left bundle branch block pattern. Attention to these criteria may lead to more rapid and effective therapy.
TL;DR: Formulas based on quantitative measurements of ST delta on the admission electrocardiogram are predictive of final QRS-estimated AMI size, and may be useful in determining the efficacy of acute reperfusion therapy.
Abstract: The decision to administer thrombolytic therapy for limitation of acute myocardial infarction (AMI) size must occur when only the history, physical examination and 12-lead electrocardiogram of a patient are available A method that could quickly assess the amount of jeopardized myocardium would greatly aid the physician This study developed formulas from 68 anterior and 80 inferior AMI patients using the extent of initial ST-segment deviation (STΔ) to predict the final AMI size estimated by the Selvester QRS score in a population not receiving reperfusion therapy Inclusion required: initial anterior or inferior AMI; admission electrocardiograpm ≤8 hours after the onset of symptoms with evidence of epicardial injury; elevated creatine kinase-MB; a predischarge electrocardiogram taken ≥72 hours after admission; and no AMI extension before the predischarge electrocardiogram The extent of epicardial injury was quantified by counting the number of leads with ≥01 mm STΔ, by the sum (Σ) of STΔ in all leads and by the ΣSTΔ in the lead groups associated with each AMI location These results were compared to the AMI size estimated from the predischarge electrocardiogram Univariable and multivariable analyses generated these formulas for AMI size: anterior = 3[15(number leads ST↑) −04]; inferior = 3[06(ΣST↑ II, III, aVF) +20] Thus, formulas based on quantitative measurements of STΔ on the admission electrocardiogram are predictive of final QRS-estimated AMI size, and may be useful in determining the efficacy of acute reperfusion therapy
TL;DR: The Thrombolysis in Myocardial Infarction trial Phase I was designed to compare the efficacy and side effects of intravenous recombinant tissue-type plasminogen activator (rt-PA) and intravenous streptokinase (SK) in patients with acute myocardial infarction, and found no significant difference in 6- and 12-month mortality.
Abstract: The Thrombolysis in Myocardial Infarction (TIMI) trial Phase I was designed to compare the efficacy and side effects of intravenous recombinant tissue-type plasminogen activator (rt-PA) and intravenous streptokinase (SK) in patients with acute myocardial infarction (AMI). As previously reported, rt-PA led to a reperfusion rate of 62% of totally occluded coronary arteries compared with 31% for SK (p less than 0.001). This study was not designed to determine if intravenous thrombolytic therapy decreases the mortality of AMI; however, the findings in these patients after 1 year of follow-up do permit certain insights into the impact of early reperfusion and reocclusion on the clinical course of patients with AMI. The mortality rate at 6 and 12 months was not significantly different in patients treated with rt-PA compared with SK (7.7% and 10.5% rt-PA vs 9.5% and 11.6% for SK). The frequency of recurrent AMI, coronary artery bypass grafting (CABG) and percutaneous transluminal coronary angioplasty (PTCA) was similar in the 2 treatment groups. There was no significant difference in 6- and 12-month mortality or in the rate of recurrent AMI in patients who received thrombolytic therapy before compared with after 4 hours of the onset of AMI symptoms. When the results were analyzed on the basis of the patency of the infarct-related artery, irrespective of thrombolytic agent used, for those patients with patent arteries 90 minutes after the initiation of therapy, there was a trend toward a lower 6-month (5.6% vs 12.5%) and 12-month mortality (8.1% vs 14.8%) (p = 0.07).(ABSTRACT TRUNCATED AT 250 WORDS)
TL;DR: The presence of clear and high no-effect doses for these toxic effects along with the fact that most of the changes observed are clearly mechanism-based indicate that it is unlikely that similar changes will be observed at the therapeutic dosage levels in humans.
Abstract: Administration of lovastatin to animals at high dosage levels produces a broad spectrum of toxicity. This toxicity is expected based on the critical nature of the target enzyme (HMG CoA reductase) and the magnitude of the dosage levels used. The information reviewed in this paper demonstrates that these adverse findings in animals do not predict significant risk in humans. The reason for this derives from the fact that all the available evidence suggests that the adverse effects observed are produced by an exaggeration of the desired biochemical effect of the drug at high dosage levels. The presence of clear and high no-effect doses for these toxic effects along with the fact that most of the changes observed are clearly mechanism-based (directly attributable to inhibition of mevalonate synthesis) indicate that it is unlikely that similar changes will be observed at the therapeutic dosage levels in humans. This hypothesis is supported by the extensive human safety experience described by Tobert in the following report.
TL;DR: Atrial fibrillation was an independent predictor of survival and its presence doubled the estimated risk over those patients without AF.
Abstract: Estimates of the prevalence of atrial fibrillation (AF) in patients with coronary artery disease have varied from "frequent" to less than 2%. Data on 18,343 patients with angiographically demonstrated CAD in the Coronary Artery Surgery Study (CASS) registry were reviewed and AF was found to be present in 116 (0.6%) patients. The presence of AF was positively associated with the following clinical and angiographic variables: older age, sex (male), mitral regurgitation and functional impairment due to congestive heart failure. The number of diseased coronary arteries was negatively related to the presence of AF. Atrial fibrillation was an independent predictor of survival and its presence doubled the estimated risk over those patients without AF.
TL;DR: In this paper, a method of predicting heart weight using 12-lead QRS amplitudes was described and the results showed that using body surface area and QRS amplitude criteria increases the accuracy of heart weight prediction.
Abstract: Serial electrocardiographic changes in necropsy-proven idiopathic dilated cardiomyopathy are evaluated and a method of predicting heart weight using QRS amplitudes is described. In 34 patients with multiple electrocardiograms (mean 3/patient) progressive prolongation of PR interval (0.18 +/- 0.03 to 0.21 +/- 0.03, p less than 0.001) and QRS duration (0.10 +/- 0.02 to 0.13 +/- 0.03, p less than 0.0001) was noted. Progressive conduction abnormalities were common (82%). QTc interval and QRS- and T-wave axes did not change. In 50 patients with electrocardiograms within 60 days of death, total 12-lead QRS and V1 through V6 QRS amplitude correlated better with heart weight (r = 0.51, p less than 0.0001 and r = 0.55, p less than 0.0001) than the Estes-Romhilt score did. The mean total 12-lead QRS amplitude was 138 mm with a mean of 106 for V1 through V6. In 31 patients cardiac mass index was calculated and showed significant correlation with 12-lead and V1 through V6 QRS amplitudes (r = 0.68, p less than 0.0001 and r = 0.75, p less than 0.0001, respectively). The QRS amplitudes remained constant during the illness. By using total 12-lead QRS or frontal plane QRS amplitude, heart weight can be predicted as early as 2 years before death. Use of body surface area and QRS amplitude criteria increases the accuracy of heart weight prediction. Thus, progressive electrocardiographic changes are common in patients with idiopathic dilated cardiomyopathy and QRS amplitude criteria are more accurate in the prediction of left ventricular hypertrophy than standard criteria.
TL;DR: Characteristic morphologic features and rapid progression of CAD in the second graft were similar to those in the primary graft.(ABSTRACT TRUNCATED at 250 WORDS)
Abstract: Development of accelerated coronary artery disease (CAD) in the cardiac allograft is one of the major causes of late graft failure in heart transplant recipients. At the Stanford University Medical Center 356 heart transplant procedures were performed in 329 patients by the end of January 1985. Eighty-nine of these patients developed evidence of transplant CAD. Twenty retransplant procedures, including 2 third transplants, were performed in 19 of the 89 patients because of transplant CAD. The graft survival rates after the second transplant were 55%, 25% and 10% after 1, 2 and 5 years, respectively. Nine of these retransplant patients currently survive, the longest for 5.5 years. To examine potential risk factors for development of severe transplant CAD, these 20 retransplant procedures were compared with 113 transplant recipients who had no evidence of transplant CAD on annual coronary arteriograms. An excess of rejection episodes (3 +/- 2 vs 2 +/- 1 episodes/patient, p = 0.02), elevated total cholesterol (266 +/- 78 vs 225 +/- 47 mg/dl, p = 0.002) and higher low-density lipoprotein levels (176 +/- 88 vs 137 +/- 46 mg/dl, p = 0.009) were noted in the transplant CAD retransplant group. Five of 11 retransplant recipients who survived greater than 1 year again developed transplant CAD. Characteristic morphologic features and rapid progression of CAD in the second graft were similar to those in the primary graft.(ABSTRACT TRUNCATED AT 250 WORDS)
TL;DR: It is suggested that brief baseline instruction followed by continuing telephone contact with staff can be used to help people adopt a moderate-intensity, home-based exercise training program that can be maintained by simple self-monitoring strategies.
Abstract: Two studies were undertaken to compare strategies for the adoption and maintenance of moderate-intensity, home-based exercise training. In the study of adoption, 52 men and women who had served for 6 months as controls for a study of moderate-intensity, home-based exercise training received 30 minutes of baseline instruction. They were then randomized to receive continuing instruction and support through 10 staff-initiated telephone contacts of 5 minutes each every 2 weeks, or to receive no telephone contacts. In subjects receiving telephone contacts, peak oxygen uptake increased significantly after 6 months, whereas no increase was observed in subjects receiving no staff support (p less than 0.05). In the maintenance study, 51 men and women who had significantly increased their peak oxygen uptake by 6 months of moderate-intensity, home-based exercise training were randomized to undergo daily self-monitoring and receive adherence instructions, or undergo weekly self-monitoring only, during a second 6-month period of training. Subjects performing daily self-monitoring reported completing significantly more exercise training sessions during the 6 months of training than subjects performing weekly self-monitoring; functional capacity in both groups remained higher than before training (p less than 0.05). Taken together, these studies suggest that brief baseline instruction followed by continuing telephone contact with staff can be used to help people adopt a moderate-intensity, home-based exercise training program that can be maintained by simple self-monitoring strategies.
TL;DR: A case of a world class powerlifter using anabolic steroids who presented with acute myocardial infarction, marked hypercholesterolemia and an abnormal LDL/HDL ratio is reported, suggesting a causal relationship to anabolic steroid use.
Abstract: A major concern facing the medical profession in dealing with athletes is the widespread use of anabolic steroids despite no proof of their effectiveness on athletic prowess* Elevated circulating levels of low density lipoprotein (LDL) cholesterol and lowered high density lipoprotein (HDL) cholesterol have recently been reported in powerlifters using anabolic steroids2 Therefore, anabolic steroid use and resultant unfavorable lipid profiles may increase the risk of cardiovascular disease We report a case of a world class powerlifter using anabolic steroids who presented with acute myocardial infarction, marked hypercholesterolemia and an abnormal LDL/HDL ratio The clinical circumstances suggest a causal relationship to anabolic steroid use A 22-year-old, 330~pound male, world class power weightlifter with no past or family history of cardiac diseases was admitted with severe chest pain that awakened him from sleep The patient was using intramuscular and oral androgenic steroids daily during the 6 weeks before he developed chest pain He denied cocaine use Physical findings on admission were normal Laboratory studies revealed elevated creatine kinase (6,182 U/ml with 15% MB band) The electrocardiogram disclosed ST-segment elevations and Q waves in leads II, III, aVF, Vs and V6 Cardiac catheterization performed 10 days after infarct demonstrated normal coronary arteries and apical dyskinesia Total serum cholesterol at admission was 596 mg/dl (LDL 513 and HDL 14 mg/dl) Twenty-four days
TL;DR: Coronary angioplasty can be performed safely and effectively in patients with chronic total occlusion, although neither the primary success rate nor the long-term follow-up are as favorable as in Patients with conventional stenoses.
Abstract: Coronary angioplasty was attempted in 1,074 consecutive patients, including 169 patients with total (100%) occlusion (group 1), 102 patients with functional total (99%) occlusion (group 2) and 711 patients with conventional (70 to 95%) stenoses (group 3). After exclusion of 92 patients with acute myocardial infarction, the mean age of the patients was 57 ± 12 years, including 727 men (74%) and 255 women (26%). Although there were no differences between groups with respect to anginal symptoms or extent of coronary artery disease, the primary success rate (by lesion) varied according to lesion severity, and was 63%, 78% and 90% for groups 1, 2 and 3, respectively (p