Cardiopulmonary Exercise Testing and Prognosis in Hypertrophic Cardiomyopathy.

Background: Exercise testing is performed in patients with hypertrophic cardiomyopathy to evaluate blood pressure response, a risk factor for sudden cardiac death. The prognostic role of exercise gas exchange variables is unknown.

Methods And Results: Between 1998 and 2010, 1898 patients (age 47±15 years, range 16-86 years; 67% male) with hypertrophic cardiomyopathy underwent cardiopulmonary exercise testing.

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.

Effect of altering pathologic right ventricular loading conditions by percutaneous pulmonary valve implantation on exercise capacity.

The data describing the change in exercise capacity after surgical or interventional management of the patient with right ventricular (RV) outflow tract (OT) dysfunction are conflicting. The pathophysiologic consequences of RVOT interventions and the subsequent change in exercise performance are still poorly understood. We sought to assess the effect of percutaneous pulmonary valve implantation (PPVI) on exercise capacity in (1) patients with predominantly pulmonary stenosis (PS) and (2) in patients with predominantly pulmonary regurgitation (PR).

Exercise-induced ventricular arrhythmias and risk of sudden cardiac death in patients with hypertrophic cardiomyopathy.

Background: Non-sustained ventricular tachycardia (NSVT) during ambulatory electrocardiographic monitoring (typically occurring at rest or during sleep) is associated with an increased risk of sudden cardiac death in patients with hypertrophic cardiomyopathy. The prevalence and prognostic significance of ventricular arrhythmias during exercise is unknown.

Methods And Results: This was a cohort study, with prospective data collection.

Biventricular response after pulmonary valve replacement for right ventricular outflow tract dysfunction: is age a predictor of outcome?

Background: The timing of pulmonary valve replacement (PVR) for free pulmonary incompetence in patients with congenital heart disease remains a dilemma for clinicians. We wanted to assess the determinants of improvement after PVR for pulmonary regurgitation over a wide range of patient ages and to use any identified predictors to compare clinical outcomes between patient groups.

Methods And Results: Seventy-one patients (mean age 22+/-11 years; range, 8.

Physiological consequences of percutaneous pulmonary valve implantation: the different behaviour of volume- and pressure-overloaded ventricles.

Aims: To investigate the early clinical and physiological consequences of relieving chronic right ventricular (RV) volume overload with percutaneous pulmonary valve implantation (PPVI).

Methods And Results: We selected 17 patients (age 21.2 +/- 8.

Usefulness of N-terminal pro-B-type natriuretic peptide levels to predict exercise capacity in hypertrophic cardiomyopathy.

Most patients with hypertrophic cardiomyopathy (HC) have reduced maximal oxygen consumption (VO2max) during exercise. The degree of impairment is poorly predicted by the magnitude of hypertrophy, left ventricular (LV) outflow tract obstruction, and other conventional markers of disease severity. The aim of this study was to determine the usefulness of N-terminal-pro-B-type natriuretic peptide (NT-pro-BNP) as a marker of exercise performance in HC.

Physiological and clinical consequences of relief of right ventricular outflow tract obstruction late after repair of congenital heart defects.

Background: Right ventricular outflow tract obstruction (RVOTO) is a common problem after repair of congenital heart disease. Percutaneous pulmonary valve implantation (PPVI) can treat this condition without consequent pulmonary regurgitation or cardiopulmonary bypass. Our aim was to investigate the clinical and physiological response to relieving RVOTO.

Reversal of inappropriate peripheral vascular responses in hypertrophic cardiomyopathy.

Objectives: We assessed the frequency of abnormal forearm vasodilator responses during lower body negative pressure (LBNP) in 21 non-obstructive hypertrophic cardiomyopathy (HCM) patients (31 +/- 8 [20 to 43] years) with abnormal blood pressure response (ABPR) to exercise and the effects of three drugs used to treat vasovagal syncope (propranolol, clonidine, and paroxetine) in a double-blind crossover study.

Background: Some HCM patients have an ABPR to exercise, which may be due to paradoxical peripheral vasodilatation. A similar proportion has paradoxical forearm vasodilatation during central volume unloading using LBNP.

Progressive left ventricular remodeling in patients with hypertrophic cardiomyopathy and severe left ventricular hypertrophy.

Objectives: The aim of this study was to determine the natural history of patients with hypertrophic cardiomyopathy (HCM) and severe left ventricular hypertrophy (LVH) (i.e., maximal left ventricular wall thickness [MLVWT] >/=30 mm) and whether changes in cardiac morphology influence the course of the disease.