Pacing biventricular

A series of pilot studies began with multisite pacing for patients with heart failure and dilated cardiomyopathy in the early 1990s [52, 105-111]. An improvement in LV function and symptoms of heart failure were demonstrated. This provided the interest in biventricular pacing for heart failure. The term cardiac resynchronization therapy was coined to refer to pacing therapies that attempt to enhance cardiac performance by using pacing to correct electrical conduction abnormalities in the heart. The most common form of this therapy is atrial-synchronous... 

Kawaguchi M, Murabayashi T, Fetics BJ, et al. Quantitation of basal dyssynchrony and acute resynchronization from left or biventricular pacing by novel echo-contrast variability imaging. J. Am. Coll. Cardiol. 2002 39 2052-8. 

Kerwin WF, Botvinick EH, O Connell JW, et al. Ventricular contraction abnormalities in dilated cardiomyopathy effect of biventricular pacing to correct interventricular dyssynchrony. J. Am. Coll. Cardiol. 2000 35 1221-7. 

Galizio NO, Pesce R, Valero E, et al. Which patients with congestive heart failure may benefit from biventricular pacing Pacing Clin. Electrophysiol. 2003 26 158-61. 

Linde C, Leclercq C, Rex S, et al. Long-term benefits of biventricular pacing in congestive heart failure results from the MUltisite STimulation in cardiomyopathy (MUSTIC) study, [see comment]. J. Am. Coll. Cardiol. 2002 40 111-8. 

Nelson GS, Berger RD, Fetics BJ, et al. Left ventricular or biventricular pacing improves cardiac function at diminished energy cost in patients with dilated cardiomyopathy and left bundle-branch block, [erratum appears in Circulation 2001 Jan 23 103 (3) 476]. Circulation 2000 102 3053-9. 

Bakker PF, Meijburg HW, de Vries JW, et al. Biventricular pacing in end-stage heart failure improves functional capacity and left ventricular function. J. Interv. Card. Electrophysiol. 2000 4 395 404. 

Leclercq C, Cazeau S, Le Breton H, et al. Acute hemodynamic effects of biventricular DDD pacing in patients with end-stage heart failure. J. Am. Coll. Cardiol. 1998 32 1825-31. 

Leclercq C, Cazeau S, Ritter P, et al. A pilot experience with permanent biventricular pacing to treat advanced heart failure, [see comment]. Am. Heart J. 2000 140 862-70. 

Cazeau S, Leclercq C, Lavergne T, et al. Effects of multisite biventricular pacing in patients with heart failure and intraventricular conduction delay. N. Engl. J. Med. 2001 344 873-80. 

Sogaard P, Kim WY, Jensen HK, et al. Impact of acute biventricular pacing on left ventricular performance and volumes in patients with severe heart failure. A tissue doppler and three-dimensional echocardio-graphic study. Cardiology 2001 95 173-82. 

Reuter S, Garrigue S, Barold SS, et al. Comparison of characteristics in responders versus nonresponders with biventricular pacing for drug-resistant congestive heart failure. Am. J. Cardiol. 2002 89 346-50. 

Patients with normal sinus rhythm and a wide QRS interval, eg, greater than 120 ms, have impaired synchronization of ventricular contraction. Poor synchronization of left ventricular contraction results in diminished cardiac output. Resynchronization, with left ventricular or biventricular pacing, has been shown to reduce mortality in patients with chronic heart failure who were already receiving optimal medical therapy. 

PATH-CHF (8) 2002 41 Dilated Cardiomyopathy NYHA III or IV QRS >120 PR >150 NSR Single blind, crossover comparison of optimized univentricular (LV only) versus biventricular pacing No difference between LV only and biventricular pacing in V02max 02 uptake at anaerobic threshold or 6MHWD. All parameters improved significantly versus baseline after 12 months. 

PAVE and OPSITE stand out among the published randomized trials of CRT in enrolling patients irrespective of pre-implant ejection fraction. In fact, nearly half of the patients in PAVE had a left ventricular ejection fraction above 45%. Post hoc analysis of PAVE suggests that the majority of the benefit in the trial was confined to the subgroup with a pre-implant ejection fraction of less than 45% (39). However, the opposite pattern was observed in OPSITE. In that trial, the comparative benefit to biventricular pacing was greatest in those patients with normal baseline left ventricular function (40). It is possible that these discordant results reflect the play of chance. A larger trial is necessary to resolve the issue. 

Duncan A, wait D, Gibson D, Daubert JC. Left ventricular remodelling and haemodynamic effects of multisite biventricular pacing in patients with left ventricular systolic dysfunction and activation disturbances in sinus rhythm substudy of the MUSTIC trial. Eur Heart J2003 24 430-41. 

Brignole M, Gammage M, Puggioni E, et al. Comparative assessment of right, left, and biventricular pacing in patients with permanent atrial fibrillation. Eur Heart J 2005 26 712-22. 

Duray GZ, Israel CW, Pajitnev D, Hohnloser SH. Upgrading to biventricular pacing/defibrillation systems in right ventricular paced congestive heart failure patients prospective assessment of procedural parameters and response rate. Europace 2008 10 48-52. 

Auricchio A, Klein H, Tockman B, et al. Transvenous biventricular pacing for heart failure can the obstacles be overcome Am J Cardiol 1999 83(5B) 136D-42D. 

Standard pacing has traditionally involved the stimulation of one or both chambers (dual-chamber) on the right side of the heart. Cardiac resynchronization therapy (CRT) typically involves pacing at least three chambers (currently the right atrium, right ventricle, and left ventricle), and is thus sometimes called biventricular pacing (Figures 11.9 and 11.10). 

Standard pacing is remarkably effective in treating bradycardia, a condition for which there is no acceptable pharmacological therapy for chronic use. Biventricular pacing is effective in the majority of patients for which it is indicated, but as many as a third of patients who receive the device are the so-called nonresponders major efforts at better defining patient selection criteria are ongoing. 

Coronary venous lead connectors were initially developed to accommodate patients with heart failure who were previously implanted for other reasons and were considered eligible for an upgrade to biventricular pacing. For these patients, the ventricular output of the PM generator was divided via a Y connector from one bipolar output to two separate outputs - one for the previously implanted RV lead and the other for the new left ventricular (LV) lead. 

Some authors recommend contralateral reimplantation as early as 36 h after extraction in patients with local symptoms only of device-related infection [10]. In some instances, it is considered safe to perform a contralateral same-day reimplantation [11]. The reasons for a same-day reimplantation are usually pacemaker (PM) dependency or hemodynamic need for CRT in case of biventricular pacing. In fact, the risk of subsequent CIED infections and venous thrombosis increases while maintaining a transvenous temporary device, and for this reason, it cannot be used indefinitely [12]. Same-day reimplantation is considered safe if the patient is clinically proven not to have active systemic bacteremia or infection by blood culture at the time of extraction and there is a lack of transesophageal echocardiographic evidence for endocarditis and the presence of a normal white blood cell count. 

When biventricular device reimplantation is necessary, we usually follow the same rules that we use in other pacing settings. Particular attention must be paid to patients with a hemodynamic dependency (to evaluate for same-day contralateral reimplantation) [15]. It is also very important to reassess the real need for CRT in patients undergoing coronary sinus (CS) lead extraction in particular, nonresponders will not be candidates to reimplantation if the previous site of pacing is considered correct, spontaneous QRS complex is narrow. 

Fig. 3.29 Loss of Biventricular Pacing. On the Y axis the atrial rate is shown. As the atrial rate exceeds the LRL, biventricular pacing is maintained. However, when the atrial rate reaches the TARP, which equals the sum of the PVARP and the AV interval, biventricular pacing will stop. However, biventricular pacing will not resume even after the atrial rate falls until the atrial rate reaches the intrinsic total atrial refractory period (ITARP), which is the sum of the PVARP and the PR interval. From Wang PJ, Kramer A, Estes NAM III, Hayes DL. Timing cycles for biventricular pacing. PACE 2002 25 52-75. (12).

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