The influence of aortoseptal angulation on provocable left ventricular outflow tract obstruction in hypertrophic cardiomyopathy.

Objectives: Aortoseptal angulation (AoSA) can predict provocable left ventricular outflow tract obstruction (LVOTO) in patients with symptomatic hypertrophic cardiomyopathy (HCM). Lack of a standardised measurement technique in HCM without the need for complex three-dimensional (3D) imaging limits its usefulness in routine clinical practice. This study aimed to validate a simple measurement of AoSA using 2D echocardiography and cardiac MR (CMR) imaging as a predictor of LVOTO.

Heart rate recovery in patients with hypertrophic cardiomyopathy.

Recovery in heart rate (HR) after exercise is a measure of autonomic function and a prognostic indicator in cardiovascular disease. The aim of this study was to characterize heart rate recovery (HRR) and to determine its relation to cardiac function and morphology in patients with hypertrophic cardiomyopathy (HC). We studied 18 healthy volunteers and 41 individuals with HC.

Cardiac output response and peripheral oxygen extraction during exercise among symptomatic hypertrophic cardiomyopathy patients with and without left ventricular outflow tract obstruction.

Objective: Reduction of left ventricular outflow tract obstruction (LVOTO) often improves symptoms in hypertrophic cardiomyopathy (HCM), but the correlation between exercise performance and measured LVOT gradients is weak. We investigated the relationship between LVOTO and cardiorespiratory responses during exercise.

Methods: The study cohort included 70 patients with HCM (32 with LVOTO, 55 male, age 47±13) attending a dedicated cardiomyopathy clinic and 28 normal volunteers.

Non-invasive assessment of cardiac output at rest and during exercise by finger plethysmography.

Aims: We sought to determine the accuracy of finger plethysmography using pulse waveform analysis with brachial calibration for measurement of cardiac output during submaximal exercise by comparing it against an acetylene (C2H2) uptake technique.

Methods: The study included 24 healthy volunteers (12 males, age 35 ± 8 years). Testing was performed on an upright cycle ergometer using an incremental protocol.