The importance of avoiding unnecessary right ventricular pacing in clinical practice

Table 4 Clinical studies of right ventricular pacing vs cardiac resynchronization therapy

Study	Design	Patient	Patients	Follow-up	Baseline LVEF	LVEF in RV	LVEF in CRT	Clinical benefit from CRT
		characteristics	(n)	(mo)		pacing
Martinelli et al[42]	RCT multicenter	AVB	60	5 (crossover)	30.1% ± 9.2%	22.5% ± 8.1%	29.3% ± 6.9%a	Improved NYHA class and QoL
Yu et al[45]	RCT multicenter	AVB and SSS	177	12	61.6% ± 6.6%	54.8% ± 9.1%	62.2% ± 7%b	No difference in hospitalization for HF, exercise capacity or QoL
Curtis et al[41]	RCT multicenter	AVB	691	37	43% ± 7% (CRT-P) 33% ± 8% (DRT-D)	-	-	Reduction in composite endpoint (mortality, HF urgent care and LVESI)
Brignole et al[47]	RCT multicenter	AVN ablation	186	20	38% ± 14%	Increasing from baseline + 4.7%	Increasing from baseline +6.6% (NS)	Reduction in composite endpoint (death from HF, hospitalization for HF or worsened HF)
Doshi et al[49]	RCT multicenter	AVN ablation	184	6	46% ± 16%	41.1% ± 13%	46% ± 13%a	Improved exercise capacity
								No difference in QoL
Orlov et al[51]	RCT multicenter	AVN ablation	127	6	56.1% ± 9.4% (CRT group) 57.2% ± 7.5% (RVP group)	54.6% ± 11.5%	59.3% ± 7.7%a	No difference in NYHA class, exercise capacity or QoL

^aP < 0.05;

^bP < 0.001 vs left ventricular function in right ventricle pacing; AVB: Atrioventricular block; AVN: Atrioventricular node; CRT-D: Cardiac resynchronization with implantable cardiac defibrillator; CRT-P: Cardiac resynchronization therapy pacing; NS: Non-significant; RVP: Right ventricular pacing; SSS: Sick sinus syndrome; QoL: Quality of life; LVEF: Left ventricular function; RV: Right ventricle; LVESI: Left ventricular end-systolic index; HF: Heart failure; RCT: Randomized controlled trial.