Left ventricular dyssynchrony from right ventricular pacing depends on intraventricular conduction pattern in intrinsic rhythm

Martin Schmidt, Harald Rittger, Harald Marschang, Anil-Martin Sinha, Marcos Daccarett, Johannes Brachmann, Michael Block, Ole A Breithardt
European Journal of Echocardiography 2009, 10 (6): 776-83

AIMS: Right ventricular pacing (RVP) prolongs ventricular activation and may induce mechanical dyssynchrony. We hypothesized that the severity of RVP-associated ventricular mechanical dyssynchrony may depend on the intrinsic intraventricular conduction pattern.

METHODS AND RESULTS: Sixty-five patients with a single- or dual-chamber RV pacemaker were included. Forty-seven patients with ejection fraction (EF) <or= 35%, 17 with no bundle branch block (BBB), 16 with right bundle branch block (RBBB), and 14 with left bundle branch block (LBBB). Eighteen patients with EF > 35% and no BBB served as a control group. Echocardiographic dyssynchrony parameters [aortic pre-ejection delay (AoPEP), interventricular mechanical delay, delayed posterior left ventricular wall motion, and septal-to-posterior wall motion delay (SPWMD)] were evaluated in all patients with and without RVP. No dyssynchrony was found in patients with no BBB, RBBB, and in the control group, whereas LBBB patients showed significant dyssynchrony in AoPEP and SPWMD. RVP had a significant negative impact on all dyssynchrony parameters in patients with no BBB or LBBB. RVP induced significantly less severe dyssynchrony in RBBB patients. With RVP 100, 94, 56 and 16% of patients with LBBB, without BBB, RBBB, and from the control group, respectively, fulfilled the CARE-HF criteria for ventricular dyssynchrony.

CONCLUSION: RVP worsens mechanical ventricular dyssynchrony in patients with reduced EF. These effects are most pronounced in patients with either normal QRS width or LBBB during intrinsic rhythm. In contrast, patients with an RBBB during intrinsic rhythm without RVP evidenced a better preserved haemodynamic function and mechanical synchrony with RVP, despite a comparable extent of pacing-induced QRS prolongation.

Full Text Links

Find Full Text Links for this Article


You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read

Save your favorite articles in one place with a free QxMD account.


Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"