Background—Cardiopulmonary exercise testing is often used to evaluate exercise capacity in adults with congenital heart disease including women who are considering pregnancy. The relationship between cardiopulmonary exercise testing parameters and pregnancy outcome has not been defined. Methods and Results—We conducted a multicenter retrospective observational study of women with congenital hea...

BACKGROUND While exercise-based cardiac rehabilitation has a beneficial effect on heart failure hospitalization and mortality, it is limited by the presence of chronotropic incompetence (CI) in some patients. This study explored the feasibility of using wearable devices to assess impaired chronotropic response in heart failure patients. METHODS Forty patients with heart failure (left ventricu...

BACKGROUND This study assessed the chronotropic response to exercise and heart rate (HR) recovery after exercise in a carefully phenotyped group of patients with heart failure with preserved left ventricular ejection fraction (HfpEF) and a control group of similar age and gender distribution. METHODS AND RESULTS We studied 41 patients with HfpEF, 41 healthy controls, and 16 hypertensive contr...

BACKGROUND The evaluation of the heart rate (HR) response to exercise is important for the assessment of the rate response algorithm of sensor-controlled pacemakers. This study examined the effects of a right ventricular impedance sensor driven pacemaker on the cardiovascular responses to incremental exercise in pacemaker dependent patients. METHODS Twelve patients (70.5 +/- 9.5 years; 5 Fema...

Biosensors play a critical role in the chronotropic regulation of rate-adaptive electronic pacemakers. However, typical pacemaker biosensors only approximate physiological function via the measurement of surrogate signals such as ventilation, and therefore can be poorly correlated with chronotropic requirements. Alternatively, the electropotential input-output relationship of cardiac myocytes c...

peaked positive chronotropic responses, i.e., rapidly induced initial acceleration followed by slowly induced but long-lasting one. The initial positive response to caffeine was hardly suppressd by either adrenergic beta-blocking agents, H 56/28 (alprenolol) and propranolol, or tetrodotoxin. On the contrary, the secondary positive chronotropic response was effectively inhibited by either adrene...

Spontaneously beating isolated atria of rabbits responded to Mn++ and Co++ with a progressively increasing negative chronotropism and inotropism, which was reversible by washout and by elevating the bath concentration of Ca++. The cumulative dose response curve for adrenaline for chronotropic response was markedly shifted to the right in the presence of Mn++ or Co++. This effect was also revers...

Immediate hemodynamic effects of beta-adrenergic blockade were determined in six normal subjects and 21 hypertensive patients following intravenous administration of propranolol. Arterial pressure was not reduced, but cardiac output fell by approximately 20% in both groups. Nevertheless, beta-adrenergic inhibition seemed to have different effects in the two groups: Propranolol produced a greate...

Ex-MR is a common mechanism across the spectrum of HF subtypes and combines with ventilatory inefficiency RV-PC uncoupling. Interestingly, in HFpEF, emerged as unexpectedly prevalent peculiarly associated increased chronotropic response peripheral O 2 extraction potential adaptive mechanisms to backward flow redistribution.