Abstract MP09: Deep Terminal Negativity of the P Wave in V1 is Associated with Sudden Cardiac Death in the Community: The Atherosclerosis Risk in Communities Study

Abstract

Background: Deep terminal negativity of the P wave in V1 (P prime in V1, PPV1) defined as PPV1 ≤ -0.1mV in amplitude and ≥40 ms in duration (one small box on ECG grid) is sign of a left atrium enlargement, and a component in the Romhilt-Estes score of left ventricular hypertrophy (LVH). LVH is known to be associated with the risk of sudden cardiac death (SCD). Deep PPV1 negativity is also associated with atrial fibrillation (AF) and stroke; both have been linked to SCD as well. However, it is unknown whether or not PPV1 negativity is independently associated with SCD. Method: Baseline resting digital 12-lead ECGs of 13232 ARIC cohort participants (mean age 53.9±5.7 y; 5760 [43.5%] men; 9747 [73.7%] white) were analyzed. Individuals with prevalent baseline coronary heart disease (CHD), heart failure (HF), or QRS ≥ 120 ms were excluded. The ECGs were analyzed using a 12SL TM algorithm (GE Healthcare, Wauwatosa, WI, USA). Amplitude and duration of PPV1 was automatically measured. Results: Deep PPV1 negativity was observed in 97 (0.73%) participants. During a median follow-up of 14 years, 182 participants had SCD. In multivariable competing risks regression analysis, deep PPV1 negativity was significantly associated with SCD after adjustment for baseline risk factors of CHD and SCD (age, sex, race, diabetes, smoking, alcohol consumption, cholesterol, triglycerides, body mass index, serum creatinine, albumin, systolic blood pressure, use of antihypertensive, QT-prolonging medications, level of physical activity, mean heart rate, QTc, QRS duration, ECG-LVH by Cornell product), and incident HF, AF, stroke [subHR 3.8 (95%CI 1.88-7.69); P<0.0001]. Deep PPV1 negativity showed 7% sensitivity and 99% specificity for SCD prediction. Conclusion: In apparently CV healthy, middle-aged individuals, deep terminal negativity of P-wave in V1 is associated with about 4-times higher risk of SCD during 14 years of follow-up. Further studies should explore the cardiac substrate underlying presence of this marker and its use for risk stratification.