Contractile response and mitral regurgitation after temporary interruption of long-term cardiac resynchronization therapy

• Published in: European heart journal 2006-01, Vol.27 (2), p.187-192
• Main Authors: Brandt, Roland R., Reiner, Christian, Arnold, Roman, Sperzel, Johannes, Pitschner, Heinz F., Hamm, Christian W.
• Format: Article
• Language: English
• Subjects: Aged; Biological and medical sciences; Cardiac Pacing, Artificial; Cardiac resynchronization therapy; Cardiology. Vascular system; Contractility; Endocardial and cardiac valvular diseases; Female; Heart; Heart failure; Heart Failure - therapy; Heart failure, cardiogenic pulmonary edema, cardiac enlargement; Humans; Long-Term Care; Male; Medical sciences; Middle Aged; Mitral regurgitation; Mitral Valve Insufficiency - etiology; Mitral Valve Insufficiency - physiopathology; Mitral Valve Insufficiency - prevention & control; Myocardial Contraction - physiology; Prospective Studies; Ventricular Dysfunction, Left - physiopathology; Ventricular Dysfunction, Left - therapy
• ISSN: 0195-668X; 1522-9645
• DOI: 10.1093/eurheartj/ehi558

Aims Cardiac resynchronization therapy (CRT) utilizing biventricular pacing (BVP) is a promising treatment modality for symptomatic patients with chronic left ventricular (LV) systolic dysfunction and intraventricular conduction delay. Clinical studies have shown short-term improvement in contractile function and mid-term improvement in clinical status with CRT. The objective of this study was to evaluate the haemodynamic consequences of temporary interruption of CRT after long-term stimulation. Methods and results Twenty patients (16 men, 4 women) with LV dysfunction and New York Heart Association class III or IV heart failure, despite optimal medical therapy and a QRS interval of at least 120 ms, received a transvenous BVP system at the age of 66 (interquartile range, 61–69). Patients were studied after a median duration of 427 days (interquartile range, 281–563) of continuous CRT and again 72 h after cessation of BVP. Withdrawal of CRT resulted in a significant decline in maximal rate of LV systolic pressure rise from 711 mmHg/s (interquartile range, 640–816) to 442 mmHg/s (interquartile range, 389–582) (P=0.0001) and increases in mitral effective regurgitant orifice area from 4.8 mm2 (interquartile range, 0.0–7.8) to 9.1 mm2 (interquartile range, 5.7–13.3) (P=0.0001), mitral regurgitant volume from 7.8 mL (interquartile range, 0.0–11.5) to 16.0 mL (interquartile range, 10.7–20.8) (P=0.0001) and fraction from 13.8% (interquartile range, 0.0–19.2) to 27.7% (interquartile range, 14.6–34.0) (P=0.0002) determined by Doppler echocardiography. Conclusion Cessation of long-term BVP leads to a decline in LV systolic performance and an increase in functional mitral regurgitation. These results indicate a sustained benefit of long-term CRT and support the notion to maintain CRT indefinitely.