Electrocardiographic QRS duration and the risk of congestive heart failure: the Framingham Heart Study
Ravi Dhingra1, Michael J Pencina, Thomas J Wang
1Framingham Heart Study, National Heart, Lung, and Blood Institute, Framingham, MA, USA.
Insights
Longer electrocardiographic QRS duration, a measure of heart depolarization, is linked to increased congestive heart failure (CHF) risk in individuals without prior heart disease. This suggests delayed electrical activation may contribute to developing CHF.
Area of Science:
- Cardiology
- Electrophysiology
- Epidemiology
Background:
- Prolonged electrocardiographic QRS duration is common in patients with congestive heart failure (CHF).
- The relationship between QRS duration and incident CHF in individuals without pre-existing heart conditions is not fully understood.
Purpose of the Study:
- To investigate whether increased QRS duration predicts the risk of developing CHF in individuals free of the condition.
- To examine the association between different categories of QRS duration and subsequent CHF incidence.
Main Methods:
- Analysis of 1759 Framingham Study participants without prior myocardial infarction or CHF.
- QRS duration assessed as a continuous (log-transformed) and categorical variable (normal, incomplete bundle branch block [BBB], complete BBB).
- Longitudinal follow-up (mean 12.7 years) to ascertain CHF development, with updated risk factors and QRS categories.
Main Results:
- CHF incidence rose across baseline QRS duration categories in both sexes.
- Each standard deviation increase in log-QRS duration correlated with a 23% higher multivariable-adjusted CHF risk.
- In time-dependent models, incomplete BBB showed a 1.4-fold and complete BBB a 1.7-fold increased CHF risk, independent of left ventricular mass.
Conclusions:
- Longer electrocardiographic QRS duration is associated with an elevated risk of developing CHF in a community-based sample.
- Depolarization delay, as indicated by prolonged QRS duration, may be a contributing factor to CHF pathogenesis.
- QRS duration is a valuable predictor of future CHF risk, even in individuals without baseline heart disease.
Abstract:
Prolonged electrocardiographic QRS duration is frequently observed in congestive heart failure (CHF) patients. We hypothesized that CHF risk increases with longer QRS interval in individuals free of CHF. We evaluated 1759 Framingham Study participants (mean age, 69 years; 63% women) without prior myocardial infarction or CHF who attended a routine examination. QRS duration was analyzed as a continuous (log-transformed) and a categorical variable [referent, <100 ms; incomplete bundle branch block (BBB), 100 to 119 ms; complete BBB, > or =120 ms]. During follow-up (mean, 12.7 years), 324 participants (205 women) developed CHF. CHF incidence increased across the 3 baseline QRS duration categories in both sexes. Each SD increment in log-QRS duration was associated with a multivariable-adjusted 23% increase in CHF risk [95% confidence interval [CI] 8% to 38%; P<0.001]. In time- dependent models with QRS category and risk factors updated every 2 years, incomplete BBB was associated with a 1.4-fold (95% CI, 1.05 to 1.96; P=0.03) and complete BBB with a 1.7-fold (95% CI, 1.28 to 2.35; P<0.001) risk of CHF. These associations were maintained on adjustment for baseline left ventricular mass. In our community-based sample, longer electrocardiographic QRS was associated with increased CHF risk, consistent with the hypothesis that depolarization delay may increase CHF risk.
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