CP32: ASSESSMENT OF REGIONAL WALL MOTION DURING RIGHT-VENTRICULAR BIFOCAL PACING IN PATIENTS WITH SEVERE CONGESTIVE HEART FAILURE

Abstract

Right-ventricular bifocal pacing (RVBF) was reported as a therapy of severe congestive heart failure. We evaluated regional wall motion by strain Doppler imaging in three patients with RVBF therapy who had conventional indication of pacemaker(70± 8 years old, mean ejection fraction 24±11%). Two dimensional SDI of the left ventricle were obtained from the apical four-chamber view during right ventricular apical pacing and RVBF pacing. Wall motion was assessed by strain of the myocardium and interval between Q-wave of surface ECG and peak of strain(QPSI) was measured in the three septal and lateral segments. Results were shown in table. RVBF pacing improves intra-ventricular contraction delay especially longitudinal dyssynchrony without improvement of left ventricle strain.

Assessment of regional wall motion
		Septal wall				Lateral wall			Whole heart
	Base	Middle	Apex	mean±SD	Base	Middle	Apex	mean±SD
Strain (%)
RVA	−10.0±8.8	−7.4±4.1	−10.9±5.0	−9.4±5.2	−9.1±6.6*	−5.9±2.7	−6.6±2.8	−7.2±3.6	−8.3±4.1
BF	−9.4±6.0	−6.1±3.9	−9.6±1.9	−8.4±3.4	−13.0±7.7*	−6.7±5.0	−12.5±9.4	−10.7 ±6.0	−9.6 ±4.4
Interval between Q-wave of surface ECG and peak strain (QPIS) (ms)
RVA	553±205	383±148*	268 ±76*	401 ±35*	627 ±73*	509 ±125	366 ±55*	500±56	451±35*
BF	541±195	470 ±89*	390 ±100*	467 ±54*	569 ±51*	521 ±50	499 ±39*	530±26	498±37*
Intraventricular contraction delay (ms)
RVA	333±238				233±118*				409±186*
BF	236±193				89±65*				296±125*

^*:p<0.05 between right ventricular apical (RVA) and bifocal pacing (BF)