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Michael Kloss

Publications and source records attributed to Michael Kloss.

3 recordsLinked to original sources
PubMed2002

Exercise performance following cardiac resynchronization therapy in patients with heart failure and ventricular conduction delay.

Patients with heart failure (HF) frequently have an impaired heart rate response to exercise and reduced oxygen consumption (VO(2)). Cardiac resynchronization therapy (CRT) has been shown to increase functional capacity in patients with HF and conduction delay. However, detailed analysis of improvement in functional capacity after CRT is still lacking. This study aimed to provide a detailed analysis of the changes in metabolic, ventilation parameters, and heart rate profiles in patients with HF and ventricular conduction delay following implantation with resynchronization devices. We provided a retrospective review on 50 patients in New York Heart Association functional class >II, with left ventricular ejection fraction <35%, on optimal medical therapy, and whose functional capacity was evaluated by cardiopulmonary exercise testing before and after CRT. Detailed analysis of VO(2), carbon dioxide production (VCO(2)), heart rate, minute ventilation (V(E) [liters per minute]), tidal volume (V(T)), respiratory rate, and heart rate profile during exercise were performed. Following CRT, peak VO(2) increased significantly from 14 +/- 4 to 17 +/- 4 (p <0.0001), and VO(2) at anaerobic threshold increased from 9 +/- 2 to 12 +/- 3 (p <0.001). All ventilation and metabolic parameters significantly increased following CRT. Similarly, heart rate at rest significantly decreased after CRT (76 +/- 12 vs 72 +/- 12 beats/min, p <0.05), whereas the maximum achieved heart rate increased significantly from 119 +/- 20 to 125 +/- 24 beats/min (p <0.05). The proportion of patients with chronotropic incompetence was significantly reduced after CRT (50% before CRT vs 34.7 after CRT; p <0.05). Patients with the baseline peak VO(2) <14 ml/kg/min benefited most from the implantation of a CRT device. In conclusion, CRT significantly improves all ventilation and metabolic parameters of patients with HF and conduction delay. Patients with more depressed metabolic and ventilation parameters and higher heart rate at baseline seem to benefit most from this therapeutic approach.

Adaptation, Physiological↗
PubMed2002

Cardiac resynchronization therapy.

Despite advances in medical therapy for patients with congestive heart failure, morbidity and mortality remain high. Conventional atrioventricular pacing with a short atrioventricular delay was first introduced as a nonpharmacologic treatment for patients with severe heart failure. Further development of this new therapeutic approach led to biventricular pacing, also known as cardiac resynchronization therapy. Many studies have been published and many are still ongoing. This review summarizes the results reported in randomized trials and focuses on questions that have not yet been answered.

Cardiac Pacing, Artificial↗
PubMed2002

Effect of cardiac resynchronization therapy on ventricular remodeling.

Cardiac resynchronization therapy (CRT) is a new non-pharmacological option for patients with advanced heart failure and ventricular conduction delay. Four randomized prospective studies have provided evidence that CRT increases exercise capacity, improves functional class and quality of life. There is also increasing evidence that CRT may trigger an inverse remodeling process leading to reduction of ventricular diameter and eventually of the atrial size. The pathophysiological mechanism throughout CRT may promote inverse remodeling is: (1) reduction of systolic and diastolic mitral regurgitation; (2) reduction of sympathetic/parasympathetic imbalance as well as reduction of neurohumoral activation due to increased systolic blood pressure and improved filling time; (3) reduction of regional wall stress. The structural changes taking place during CRT are directly related to continuous pacing, because lack of pacing immediately shows the new onset of remodeling. The duration of the reported changes of ventricular diameter is still unknown, and it is also unknown whether such reverse remodeling process of the ventricle and of the atria will lead to a reduction of cardiac death and incidence of ventricular arrhythmias.

Cardiac Pacing, Artificial↗