Relation of Left Ventricular Chamber Stiffness at Rest to Exercise Capacity in Hypertrophic Cardiomyopathy

• Published in: The American journal of cardiology 2007-05, Vol.99 (10), p.1454-1457
• Main Authors: Dumont, Carlos Alberto, MD, Monserrat, Lorenzo, MD, Peteiro, Jesús, MD, Soler, Rafaela, MD, Rodriguez, Esther, MD, Bouzas, Alberto, MD, Fernández, Xusto, MD, Pérez, Ruth, MD, Bouzas, Beatriz, MD, Castro-Beiras, Alfonso, MD
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Age Factors; Aged; Analysis of Variance; Cardiology; Cardiomyopathy, Hypertrophic - diagnosis; Cardiomyopathy, Hypertrophic - etiology; Cardiomyopathy, Hypertrophic - physiopathology; Cardiovascular; Contrast Media; Echocardiography, Doppler, Color; Exercise; Exercise Test; Exercise Tolerance; Female; Gadolinium DTPA; Heart; Heart failure; Heart Rate; Humans; Hypertrophy, Left Ventricular - complications; Hypertrophy, Left Ventricular - diagnosis; Hypertrophy, Left Ventricular - physiopathology; Magnetic Resonance Imaging, Cine; Male; Middle Aged; Pulmonary Wedge Pressure; Regression Analysis; Research Design; Rest; Sensitivity and Specificity; Severity of Illness Index; Stroke Volume; Ultrasonic imaging; Vascular Resistance; Ventricular Dysfunction, Left - complications; Ventricular Dysfunction, Left - diagnosis; Ventricular Dysfunction, Left - physiopathology
• ISSN: 0002-9149; 1879-1913
• DOI: 10.1016/j.amjcard.2006.12.077

The degree of exercise capacity is poorly predicted by conventional markers of disease severity in patients with hypertrophic cardiomyopathy (HC). The principal mechanism of exercise intolerance in patients with HC is the failure of stroke volume augmentation due to left ventricular (LV) diastolic dysfunction. The role of LV chamber stiffness, assessed noninvasively, as a determinant of exercise tolerance is unknown. Sixty-four patients with HC were studied with Doppler echocardiography, exercise testing, and gadolinium cardiac magnetic resonance. The LV chamber stiffness index was determined as the ratio of pulmonary capillary wedge pressure (derived from the E/Ea ratio) to LV end-diastolic volume (assessed by cardiac magnetic resonance). Maximal exercise tolerance was defined as achieved METs. There were inverse correlations between METs achieved and age (r = −0.38, p = 0.003), heart rate deficit (r = −0.39, p = 0.002), LV outflow tract gradient (r = −0.33, p = 0.009), the E/Ea ratio (r = −0.4, p = 0.001), mean LV wall thickness (r = −0.26, p = 0.04), and LV stiffness (r = −0.56, p