Background— Nonobstructive hypertrophic cardiomyopathy (HCM) has been regarded as the predominant hemodynamic form of the disease on the basis of assessment of outflow gradient under resting conditions. We sought to prospectively define the prevalence, clinical profile, and significance of left ventricular (LV) outflow tract obstruction under resting conditions and with physiological exercise in a large HCM cohort. Methods and Results— We prospectively analyzed 320 consecutive HCM patients (age, 47±17 years), measuring LV outflow gradient at rest, with Valsalva maneuver, and with exercise echocardiography. LV outflow obstruction was present at rest and/or with exercise in 225 patients (70%); 119 had rest gradients ≥50 mm Hg and were not exercised. Of the other 201 patients with gradients <50 mm Hg at rest (average, 4±9 mm Hg), 106 developed mechanical obstruction to LV outflow resulting from mitral valve–septal contact after exercise (80±43 mm Hg), including 76 with marked gradients ≥50 mm Hg and 46 with heart failure symptoms. The remaining 95 patients (30%) had no or small gradients (<30 mm Hg) both at rest and with exercise. Valsalva maneuver underestimated the presence and magnitude of exercise-induced obstruction. Conclusions— Among those patients who come to clinical evaluation, HCM is a predominantly obstructive disease in which LV outflow gradients, frequently associated with heart failure symptoms and often identified only with exercise, are evident in most patients (ie, 70%). Identification of LV outflow obstruction with exercise echocardiography may broaden management options in HCM by identifying symptomatic patients not otherwise regarded as potential candidates for septal reduction therapy. Assessment of subaortic gradients with exercise should be a routine component of the evaluation of HCM patients without outflow obstruction under resting conditions.

OBJECTIVE To evaluate the dimensions of the aortic root in a selected population of young males with isolated normally functioning bicuspid aortic valve. DESIGN AND SETTING Echocardiographic and Doppler evaluation of conscripts with bicuspid aortic valve at the time of military pre-enrolment screening in two military hospitals. SUBJECTS AND METHODS 66 consecutive young men with a normally functioning bicuspid aortic valve were studied to assess aortic size at four aortic levels: annulus, sinuses of Valsalva, supra-aortic ridge, and proximal ascending aorta; 70 consecutive normal young subjects, matched for age and body surface area, were used as controls. RESULTS In men with a bicuspid aortic valve, the diameter of the aortic root was significantly larger than in controls at the sinuses (3.16 (0.37)v 2.87 (0.31) cm, p < 0.001), at the supra-aortic ridge (2.64 (0.46) v 2.47 (0.28) cm, p = 0.01), and at the level of the proximal ascending aorta (3.12 (0.48) v 2.69 (0.28) cm, p < 0.001). The prevalence of aortic root dilatation was 7.5% at the annulus (5/66), 19.6% at the sinuses (13/66), 15% at the supra-aortic ridge (10/66), and 43.9% at the ascending aorta (29/66); 32 subjects (48%) had aortic root dimensions comparable with controls, while 34 (52%) had definitely abnormal aortic root dimensions. CONCLUSIONS Aortic root enlargement in people with a bicuspid aortic valve occurs independently of haemodynamic abnormalities, age, and body size. However, there appear to be different subgroups of young adults with bicuspid aortic valves, one of which is characterised by aortic dilatation, possibly caused by a congenital abnormality of the aortic wall.

Vasodilator therapy with nifedipine reduces left ventricular volume and mass and increases the ejection fraction in asymptomatic patients with severe aortic regurgitation.

To investigate the relation between aortic elastic properties and size in bicuspid aortic valves (BAVs). 127 BAV outpatients (121 males; age 23 ± 10 years) with no or mild valvular impairment, were recruited with 114 control subjects comparable for age, gender, and body size. Aortic distensibility (DIS) and stiffness index (SI) were derived by M-mode evaluation of the aortic root together with blood pressure measured by cuff sphygmomanometer. BAVs vs. controls had increased aortic diameter (P < 0.0001), higher systolic (P = 0.02) and pulse (P = 0.04) pressures. DIS was lower in BAVs than in controls (4.71 ± 3.67 vs. 7.44 ± 3.94 10⁻⁶ cm²dyne⁻¹, respectively; P < 0.0001) and SI was greater in BAVs (7.21 ± 4.93 vs. 3.57 ± 1.88, respectively; P < 0.0001). Definite impairment in aortic elasticity was present in 53 (42%) BAVs. Both DIS and SI were related (P < 0.0001) to aortic size in BAVs and controls. After adjusting for aortic size and blood pressure, the regression relations between SI and aortic diameter of BAVs were significantly different from controls (P = 0.0052). Abnormal aortic elasticity is a common finding in BAVs with no or mild aortic valve impairment. However, impaired aortic stiffness is not due to aortic dilation. Simple assessment of aortic size may thus fail to identify early abnormal load bearing characteristics of the aortic wall in BAVs.