Showing papers in "Current Opinion in Cardiology in 1987"

The effects of ageing and arterial hypertension on the heart and arterial compliance

Abstract: Ageing and long-standing arterial hypertension produce almost indistinguishable pathoanatomical changes in the major target organs such as the brain, the heart and the kidneys. Arterial hypertension seems, therefore, to set the biological clock of the vascular tree at a faster pace. Left ventricular hypertrophy, nephrosclerosis and cerebral vascular damage can be found in elderly normotensive subjects but are greatly accelerated in patients with essential hypertension. Arterial compliance is reduced with age and long-standing hypertension, leading to a disproportionate increase in systolic blood pressure. Arterial compliance may become reduced to the degree that it interferes with accurate blood pressure estimation by cuff, a phenomenon known as pseudohypertension. Antihypertensive therapy should not only lower arterial pressure but improve vascular compliance and prevent target organ disease or allow existing target organ damage to regress.

Isolated systolic hypertension

Abstract: Isolated systolic hypertension is commonly defined as ≥160 mmHg systolic and <90 mmHg diastolic blood pressure, although other definitions are used as well. There is a bimodal distribution of isolated systolic hypertension. Young borderline hypertensives with hyperkinetic circulation may have isolated systolic hypertension. The exact prevalence is not known but it is estimated to occur in <1/3 of young borderline hypertensives. In an elderly population the prevalence of isolated systolic hypertension is considerably higher, perhaps >25% in the entire population aged ≥65 years in the USA. Recent data from the Systolic Hypertension in the Elderly Program (SHEP) in the USA indicate that isolated systolic hypertension occurs in 7–20% of elderly people aged ≥60 years, and in the screening for the Swedish Trial of Old Patients with Hypertension (STOP-Hypertension) in Sweden 4% of all men and women aged 70–84 years exhibited isolated systolic hypertension, defined as ≥180/<90 mmHg. In the young borderline-hypertensive group, isolated systolic hypertension can be attributed to increased sympathetic drive leading to tachycardia and increased cardiac output, whereas in the elderly, isolated systolic hypertension is caused by reduced compliance in the aorta and large arteries. In isolated systolic hypertension, the elevated systolic blood pressure produces an increased workload for the left ventricle, while the low/normal diastolic blood pressure may lead to suboptimal coronary perfusion. Systolic blood pressure is a better indicator of cardiovascular risk than diastolic blood pressure, but there are still no firm data that show benefits from treatment of isolated systolic hypertension. It is to be hoped that the ongoing SHEP study will clarify this point.

Transposition of the Great Arteries

Abstract: The first approach to physiologic correction of transposition of the great arteries, based on transposing venous inflow, was conceived by Albert,3 using animal experiments, and reported in 1954. Senning64 reported in 1959 a successful intraatrial operation in humans utilizing the walls and septum of the atria. Shumacker68 described in 1961 an operation using a bipedicled atrial flap. Mustard’s report47 in 1964 of an intraatrial transposition operation in a human using pericardium led to its almost universal use during the late 1960s and early 1970s. The 1970s saw a widespread return to the Senning operation in hopes of decreasing or eliminating some of the complications seen with the Mustard operation.10,20,50,53

Intrinsic alterations of the arterial wall in hypertension and effect of antihypertensive therapy

Abstract: Therapeutic trials in hypertension indicate that cardiovascular morbidity and mortality are reduced by antihypertensive drug treatment but that the incidence of arterial ischaemic accidents remains elevated, in particular in the coronary circulation. Non-invasive haemodynamic studies in untreated uncomplicated hypertensive patients show that intrinsic alterations of large arterial vessels do exist in hypertension. These alterations involve reduced arterial compliance and hyper-responsiveness to vaso-constrictive stimuli. Various antihypertensive drugs causing the same blood pressure reduction act differently on large arterial vessels. Following drug therapy, arterial compliance may be increased (converting enzyme inhibitor) or decreased (dihydralazine). These findings may be relevant for the understanding of cardiovascular morbidity and mortality in patients treated for hypertension.

Systolic blood pressure reduction with lisinopril (MK-521) in elderly patients with essential arterial hypertension

Abstract: Lisinopril (MK-521) is a new long-acting, non-sulphydryl, angiotensin converting enzyme (ACE) inhibitor that reduces blood pressure in hypertensive subjects. Low plasma renin and other factors can impair blood pressure reduction in the elderly (>65 years old) during ACE inhibitor treatment. Lisinopril studies have shown pharmacokinetic differences between elderly and non-elderly subjects. Peak serum lisinopril concentration is twice as high in the elderly compared with the non-elderly and there is a slight delay in reaching the maximum drug concentration in the elderly. During four 12-week, multicentre, double-blind protocols with 1168 subjects, 139 elderly hypertensive patients were studied to compare lisinopril (20–80 mg/day) with hydrochlorothiazide (HCTZ 12.5–50 mg/day) alone, with lisinopril + HCTZ combined (20+ 12.5 to 80 + 50 mg/day, respectively), and separately with atenolol (50–200 mg/day), metoprolol (100–200 mg/day) and nifedipine (40–80 mg/day). When compared to baseline blood pressure in all four studies, reductions in sitting diastolic blood pressure and sitting systolic blood pressure were significant (P; ≤ 0.01 to ≤ 0.05) for all drug treatments. During all four studies lisinopril reduced sitting diastolic blood pressure by 11.1–17.7 mmHg and sitting systolic blood pressure by 21.0–26.1 mmHg. The other four monotherapy drug regimens lowered sitting diastolic blood pressure by 9.0–21.0 mmHg and sitting systolic blood pressure by 14.2–34.2 mmHg, but there were no significant differences when lisinopril was compared with HCTZ, atenolol, metoprolol or nifedipine in either elderly or non-elderly patients. There were no serious adverse drug effects during lisinopril treatment. These data suggest that lisinopril is effective and well tolerated for the reduction of both systolic and diastolic blood pressure in elderly patients with uncomplicated essential hypertension.

Relationship between risk of stroke and systolic blood pressure in mild hypertension: observations from the Medical Research Council trial

Abstract: A total of 8654 mildly hypertensive men and women received placebo treatment in the Medical Research Council (MRC) trial. After 6 months their mean blood pressure had fallen by 20.8/10.8 mmHg, and in 13.8% of patients systolic pressure was now lower than 135 mmHg. The level of systolic blood pressure before and after this fall was used to predict all-cause mortality and risks of stroke and ischaemic heart disease. Our analysis was concerned with the relationship between arterial pressure and the risk of stroke. For patients with low levels of blood pressure on placebo treatment, the risk of stroke was lower. For patients who remained in the highest blood pressure category, the risk for a given level of pressure increased. A total of 4297 patients were given 10 mg bendrofluazide daily. Analysis by intention-to-treat showed fewer strokes, the extent of the benefit being greater than could be explained by the reduction of systolic pressure as measured after 6 months. Propranolol given in graded doses to a similar number of patients had a similar but less pronounced beneficial effect.