American College of Cardiology/European Society of Cardiology Clinical Expert Consensus Document on Hypertrophic Cardiomyopathy: a report of the American College of Cardiology Foundation Task Force on Clinical Expert Consensus Documents and the European Society of Cardiology Committee for Practice Guidelines

Hypertrophic cardiomyopathy. The importance of the site and the extent of hypertrophy. A review

This document has been developed as a Clinical Expert Consensus Document (CECD), combining the resources of the American College of Cardiology Foundation (ACCF) and the European Society of Cardiology (ESC). It is intended to provide a perspective on the current state of management of patients with hypertrophic cardiomyopathy. Clinical Expert Consensus Documents are intended to inform practitioners, payers, and other interested parties of the opinion of the ACCF and the ESC concerning evolving areas of clinical practice and/or technologies that are widely available or new to the practice community. Topics chosen for coverage by expert consensus documents are so designed because the evidence base, the experience with technology, and/or the clinical practice are not considered sufficiently well developed to be evaluated by the formal American College of Cardiology/American Heart Association (ACC/AHA) Practice Guidelines process. Often the topic is the subject of considerable ongoing investigation. Thus, the reader should view the CECD as the best attempt of the ACC and the ESC to inform and guide clinical practice in areas where rigorous evidence may not yet be available or the evidence to date is not widely accepted. When feasible, CECDs include indications or contraindications. Some topics covered by CECDs will be addressed subsequently by the ACC/AHA Practice Guidelines Committee.

The Task Force on Clinical …

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American College of Cardiology/European Society of Cardiology clinical expert consensus document on hypertrophic cardiomyopathy: a report of the American College of Cardiology Foundation Task Force on Clinical Expert Consensus Documents and the European Society of Cardiology Committee for Practice Guidelines

HCM is a heterogeneous disease genotypically, phenotypically, pathophysiologically, clinically, and therapeutically. In decisions on the management of these patients, it is important to recognize this heterogeneity and to direct therapy at the predominant abnormalities.

Hypertrophic Cardiomyopathy Clinical Spectrum and Treatment

Retrospective analysis of the clinical course of 254 patients with hypertrophic cardiomyopathy, followed up for 1 to 23 years (mean 6), disclosed that 58 had died, 32 of them suddenly. The 196 survivors were compared with the 32 patients who died suddenly and with the 38 who died suddenly or with heart failure. The combination of young age (14 years or less), syncope at diagnosis, severe dyspnea at last follow-up and a family history of hypertrophic cardiomyopathy and sudden death best predicted sudden death (false negative rate 30 percent, false positive rate 27 percent). A "malignant" family history was associated with poor prognosis, particularly in the younger patients; a family history of hypertrophic cardiomyopathy without sudden death was more frequent in the survivors (12 percent) than in the dead (5 percent). Patients who had a diagnosis in childhood were usually asymptomatic, had an unfavorable family history and a 5.9 percent annual mortality rate. In those aged 15 to 45 years at diagnosis, there was a 2.5 percent annual mortality rate and syncope was the only prognostic feature. Among those diagnosed between age 45 and 60 years, dyspnea and exertional chest pain were more common in the patients who died, and the annual mortality rate was 2.6 percent. Poor prognosis was better predicted by the history at the time of diagnosis and by changes in symptoms during follow-up than by an electrocardiographic or hemodynamic measurement.

Prognosis in hypertrophic cardiomyopathy: Role of age and clinical, electrocardiographic and hemodynamic features

Twenty-two patients with hypertrophic obstructive cardiomyopathy were treated with the calcium inhibitor, verapamil, which was administered in a mean oral dose of 480 mg per day. After an average of 15 months of treatment (4 to 24 months), the QRS amplitude in the electrocardiogram was significantly reduced from 4.2 to 3.8 mV. Heart volume calculated from chest x-ray films in the supine position decreased significantly from 858 to 766 ml per 1.73 m2. In 10 patients, follow-up heart catheterisation showed a decrease in left ventricular muscle mass in 7 patients and a slight increase in 3 patients. Coronary artery diameter decreased in 7 patients, increased in 1, and was unchanged in 2. The reduction in coronary artery diameter is considered to be a consequence of a reduced heart muscle mass. From all available clinical data it is concluded that verapamil treatment is superior to beta-blocker therapy.

https://heart.bmj.com/content/heartjnl/42/1/35.full.pdf

Treatment of hypertrophic obstructive cardiomyopathy with verapamil.

Transluminal coronary angioplasty (TCA) was introduced in 1977 for dilatation of coronary stenoses. From October 1977 to December 1984 1087 procedures have been performed in Frankfurt. The mean success rate was 77% with an increase from 58% to 84% since 1977. Recurrences were seen within the first year in 15% of the patients, which could be treated successfully in a high percentage with a second TCA. Emergency bypass operations were necessary in 5.2%. Four patients (fatality rate 0.37%) died as consequence of the intervention. Within few years TCA has become an established procedure for myocardial revascularisation, with a high success rate. Major progress has been possible in the last few years due to technical developments, which are still going on. They may lead to further improvement of the results and enlargement of the indication for TCA.

[Transluminal coronary angioplasty 1977-1985. Experience with 1000 interventions].

First described in the last century, HOCM is recognized today in a considerable number of patients. The severity of the disorder varies between severe disablement to a completely asymptomatic clinical picture.

Verapamil Treatment of Hypertrophic Obstructive Cardiomyopathy

The validation of parameters of left ventricular contractility at rest is pure. Therefore, the contractile function of the left ventricle was measured during exercise. The reserve in contractility and relaxation was obtained in a group of 13 patients with normal left ventricle (ergometer). The maximal rate of left ventricular pressure rise (max dP/dt) increased from 1721 +-378 to 4954 +- 1246 mmHg/s and the peak measured velocity of contractile elements (dP/dt/P) from 38 +- 9 to 76 +- 11 s-1 at a mean load of 112 +- 43 (+-SD) watts. The parameter of the isovolumic relaxation phase, the maximal rate of left ventricular pressure fall (min dP/dt) increased from 1862 +- 343 to 3128 +- 445 mmHg/s. Left ventricular enddiastolic pressure was unchanged. All patients reached at least 3200 mmHg/s (max dP/dt) 60 s-1 (dP/dt/P) and 2400 mmHg/s (min dP/dt). The difference between rest- and exercise values was at least 1800 mmHg/s (max dP/dt), 22 s-1 (dP/dt/P) and 1000 mmHg/s (min dP/dt).

[Contractile and relaxation reserve of the left ventricle. I. Normal left ventricle (author's transl)].

51 patients with coronary heart disease had exercise tests on a bicycle ergometer (86 +/- 32 watts). Compared to a normal control group, only 13 patients had normal contractile reserve (group 4.1). In 32 patients the increase in contractility during exercise was reduced (max dP/dt below 3200 mm Hg/s, group 4.2). Patients with reduced contractile reserve were graded according to the height of left ventricular enddiastolic pressure during exercise: In patients with grade 1, enddiastolic pressure was normal. In patients with grade 2, enddiastolic pressure increased between + 4 and + 15 mm Hg and in the patients with grade 3a a above + 15 mm Hg. Contractile and relaxation reserve decreased along with a rise in enddiastolic pressure and an increase in the complaints of the patients. Severe chest pain led to termination of exercise in patients of grade 3b. Enddiastolic pressure increased above + 15 mm Hg. During ischemia, peak-measured velocity of contractile elements (dP/dt/P) and the maximal rate of left ventricular pressure fall (min dP/dt) decreased. In conclusion, with increasing chest pain a decrease of contractile reserve was observed. Left ventricular enddiastolic pressure rose excessively. This has to be taken as a sign of myocardial failure due to ischemic dyskinesia and impeded relaxation.

Bussmann Wd

Papers

Treatment of hypertrophic obstructive cardiomyopathy with verapamil.

[Transluminal coronary angioplasty 1977-1985. Experience with 1000 interventions].

Verapamil Treatment of Hypertrophic Obstructive Cardiomyopathy

[Contractile and relaxation reserve of the left ventricle. I. Normal left ventricle (author's transl)].

[Contractile and relaxation reserve of the left ventricle. IV. Patients with coronary heart disease (author's transl)].