Delayed intrinsicoid deflection of the QRS complex is associated with sudden cardiac arrest

Abstract

Background Prolongation of initial ventricular depolarization on the 12-lead ECG, or delayed intrinsicoid deflection (DID), can indicate left ventricular hypertrophy (LVH). The possibility that this marker could convey distinct risk of sudden cardiac arrest (SCA) has not been evaluated. Objective To evaluate the association of DID and SCA in the community. Methods In the ongoing prospective, population-based Oregon Sudden Unexpected Death Study (Oregon SUDS, catchment area approx. 1 million), SCA cases were compared to geographic controls with no SCA. Archived ECGs (closest and unrelated to SCA event for cases) were evaluated for the presence of DID defined as ≥0.05 seconds in leads V5 or V6. LV mass and function were evaluated from archived echocardiograms. Results SCA cases (n=272, 68.7±14.6 years, 63.6% male) as compared to controls (n=351, 67.6±11.4 years, 63.3% male) were more likely to have DID on ECG (28.3% vs 17.1%, p=0.001). DID was associated with increased SCA odds (OR 1.92; 95% CI 1.31-2.81; p=0.001), but showed poor correlation with LV mass and echocardiographic LVH (kappa 0.13). In multivariate analysis adjusted for clinical and ECG markers, reduced LV ejection fraction and echocardiographic LVH, DID remained an independent predictor of SCA (OR 1.82; 95% CI 1.12-2.97; p=0.016). Additionally, in a sensitivity analysis restricted to narrow QRS, DID and ECG LVH by voltage were each independently associated with SCA risk. Conclusion DID was associated with increased SCA risk independent of echocardiographic LVH, ECG LVH and reduced LV ejection fraction, potentially reflecting unique electrical remodeling that warrants further investigation.

The Romhilt‐Estes electrocardiographic score predicts sudden cardiac arrest independent of left ventricular mass and ejection fraction

“…It is made up of nine individual criteria determined from the 12‐lead ECG, with RE score of 4 being labeled as probable LVH and a score of 5 or greater as definite LVH (Romhilt & Estes, ). In addition to diagnosing LVH, the RE score has been shown to predict adverse cardiovascular events and all‐cause mortality (Estes, Zhang, Li, Tereschenko, & Soliman, ; Estes, Zhang, Li, Tereshchenko, & Soliman, ), and we recently demonstrated that one component of the RE score, delayed intrinsicoid deflection, was independently predictive of SCA (Darouian et al., ). However, little data exists on the performance of the other individual components, or the RE score as a whole as a predictor of SCA.…”

“…We evaluated the relationship of the RE score and SCA from the Oregon Sudden Unexpected Death Study (Oregon SUDS). The details of this ongoing study have been published previously (Chugh et al., ; Darouian et al., ; Narayanan et al., ; Teodorescu et al., ). Cases and controls in the study were enrolled from the Portland, Oregon metropolitan area consisting of a population of approximately one million individuals.…”

“…There are over 300,000 estimated deaths annually in the United States due to sudden cardiac arrest (SCA; Mozaffarian et al., ), thus identifying subjects at increased risk for SCA has been a focus of intensive research with the goal of reducing this burden (Bardy et al., ; Buxton et al., ; Epstein et al., ; Moss et al., , ). The 12‐lead electrocardiogram (ECG) is a widely available diagnostic tool with several depolarization and repolarization abnormalities already associated with increased risk of SCA (Algra, Tijssen, Roelandt, Pool, & Lubsen, ; Aro et al., ; Chugh et al., ; Darouian et al., ; Straus et al., ; Teodorescu et al., ). Although the 12‐lead ECG has limited ability to detect increased left ventricular (LV) mass, we have recently demonstrated that electrocardiographic left ventricular hypertrophy (LVH) by Sokolow–Lyon voltage criteria was associated with SCA independent of anatomic LVH (Narayanan et al., ).…”

Einthoven and electrical risk: Value of the electrocardiogram to predict sudden cardiac death

“…These findings suggest that increased myocardial voltage likely represents adverse “electrical” remodeling, conferring a risk that is distinct from the “anatomic” remodeling of echocardiographic LV hypertrophy . Delayed intrinsicoid deflection (DID) of the QRS complex is an ECG marker that contributes to risk of arrhythmogenesis independent of anatomic increase in LV mass . Delayed QRS transition zone (R‐wave transition at V5 or V6) is another abnormal ECG marker associated with increased SCD risk, likely caused by a pathophysiology that extends beyond previous myocardial infarction and reduced LVEF .…”

“…10 Delayed intrinsicoid deflection (DID) of the QRS complex is an ECG marker that contributes to risk of arrhythmogenesis independent of anatomic increase in LV mass. 11 Delayed QRS transition zone (Rwave transition at V5 or V6) is another abnormal ECG marker associated with increased SCD risk, likely caused by a pathophysiology that extends beyond previous myocardial infarction and reduced LVEF. 12 Manifestations of abnormal myocardial repolarization have also been linked to increased risk of SCD.…”