EVALUATION OF LEFT VENTRICULAR CONTRACTILITY IN HYPERTROPHIC CARDIOMYOPATHY FROM END-SYSTOLIC PRESSURE-VOLUME RELATION

• Published in: JAPANESE CIRCULATION JOURNAL Vol. 51; no. 5; pp. 511 - 519
• Main Authors: KAKU, KIYOTAKA, KAWAMURA, KEISHIRO, KITA, YOSHIO, SAITO, TAKAHARU, SHIMIZU, GEN, HIROTA, YUZO
• Format: Journal Article
• Language: English
• Published: Kyoto The Japanese Circulation Society 1987; Japanese Circulation Society; 社団法人日本循環器学会
• Subjects: Adult; Biological and medical sciences; Blood Pressure; Blood Volume; Cardiology. Vascular system; Cardiomyopathy, Hypertrophic - physiopathology; End-systolic pressure-volume relation; Heart; Heart Ventricles; Humans; LV contractility; Medical sciences; Middle Aged; Myocardial Contraction; Myocarditis. Cardiomyopathies; Stress-shortening relation; Systole; Heart; Human; Cardiac performance; Pressure volume ratio; Hypertrophic cardiomyopathy; Cardiovascular disease; Hemodynamics; End-systolic pressure; Myocardial disease; End-systolic volume; Left ventricle
• ISSN: 0047-1828; 1347-4839
• DOI: 10.1253/jcj.51.511

To evaluate myocardial contractility in hypertrophic cardiomyopathy (HC), we obtained the end-systolic pressure-volume relation (ESPVR) and the end-systolic stress-volume relation (ESSVR) by changing loading conditions with Angiotensin II. The left ventricular (LV) stress-shortening relation was also analyzed in order to assess myocardial contractility. LV end-systolic pressure, end-systolic volume, end-systolic stress, and ejection fraction were obtained at rest and during Angiotensin II infusion with simultaneous recordings of pressure and volume in 9 patients with hypertrophic cardiomyopathy and 9 normal subjects (N). The slopes of ESPVR, Emax, showed no significant difference (HC: 3.1±2.3 vs N: 2.6±1.4 mmHg/ml, ns). The slopes of ESSVR were statistically similar (HC: 5.2±2.1 vs N: 6.0±2.8 g/cm2 ml, ns). The slopes of end-systolic stress-ejection fraction relation were also in the same range in both groups (HC: -0.09±0.05 vs N: -0.10±0.05, ns). From these two different analyses of LV contractility, we conclude that myocardial contractility is normal in hypertrophic cardiomyopathy and not supernormal, at both chamber and muscle levels. Considering the increased muscle mass in hypertrophic cardiomyopathy (HC: 13446 vs N: 7419 g/m2, p<0.01), the presence of increased numbers of contractile unites does not result in enhanced overall chamber contractility.