JOURNAL ARTICLE

Left ventricular conduction delays and relation to QRS configuration in patients with left ventricular dysfunction

Niraj Varma
American Journal of Cardiology 2009 June 1, 103 (11): 1578-85
19463519
Left ventricular activation delay (LVAT) >100 ms may determine response to cardiac resynchronization therapy, but its prevalence and relation to QRS configuration are unknown. QRS duration and LVAT in control subjects (n = 30) were compared with those in patients with heart failure (HF; LV ejection fraction 23 +/- 8%, n = 120) with a QRS duration <120 ms (NQRS(HF), n = 35) or > or = 120 ms (left bundle branch block [LBBB(HF)], n = 54; right bundle branch block [RBBB(HF)], n = 31). LVAT was estimated by interval from QRS onset to basal inferolateral LV depolarization. In controls, QRS duration was 82 +/- 13 ms and LVAT was 55 +/- 18 ms. LVAT was always <100 ms. In patients with NQRS(HF), QRS duration (104 +/- 10 ms) and LVAT (82 +/- 22 ms) were prolonged versus controls (p <0.001). LVAT exceeded 100 ms in 8 of 35 patients. In patients with LBBB(HF), QRS duration (161 +/- 29 ms) and LVAT (136 +/- 33 ms) were prolonged compared with controls and patients with NQRS(HF) (p <0.001). LVAT exceeded 100 ms in 47 of 54 patients. In patients with RBBB(HF), QRS duration did not differ from that in patients with LBBB(HF), but LVAT (100 +/- 24 ms) was shorter (p <0.001). In 17 of 31 patients with RBBB(HF) LVAT was <100 ms (82 +/- 12), similar to those with NQRS(HF) (p = NS), indicating no LV conduction delay. However, in 7 of 31, LVAT (135 +/- 13 ms) was similar to that in patients with LBBB(HF) (p = NS). LVAT correlation with QRS duration varied (control p = 0.004, NQRS(HF) p = 0.15, RBBB(HF) p = 0.01, LBBB(HF) p <0.001). In conclusion, LV conduction delays in patients with HF varied with QRS configuration and duration, exceeding 100 ms in only 23% of patients with narrow QRS configuration and 45% with RBBB(HF) compared with 87% with LBBB(HF). Fewer than 25% of patients with RBBB(HF) demonstrated delays equivalent to those in patients with LBBB(HF.) These variations may affect efficacy to cardiac resynchronization therapy.

Full Text Links

Find Full Text Links for this Article

Discussion

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

Related Papers

Remove bar
Read by QxMD icon Read
19463519
×

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"