Time Course of Changes in P-Wave Duration during Exercise

Abstract

The exercise-induced increase in P-wave duration reported previously has not been studied on a minute-by-minute basis. We measured the P duration in 47 normal subjects and 43 coronary artery disease (CAD) patients each minute during an exercise test. We found that prolongation of the P wave in those with CAD occurs relatively early and the difference between normal subjects and CAD patients is greater near maximum exercise. The data suggest that an increase in P-wave duration may reflect an increase in the left-ventricular end-diastolic pressure and may occur earlier that ST-segment depression.

Exercise Standards for Testing and Training

“…Even though these findings are not used in routine test interpretation, they are described briefly in the P-Wave Abnormalities. Among patients with chest pain evaluated by myocardial perfusion imaging, exercise-related P-wave duration and terminal P-wave amplitude in V 1 have been reported to be greater in patients with reversible ischemia than in patients with normal scans, [120][121][122] a finding that might be attributed to left atrial pressure overload during ischemia. An increase in P-wave duration by signal-averaging has also been associated with ischemia.…”

Filtered signal-averaged P-wave duration during pneumoperitoneum in patients undergoing laparoscopic cholecystectomy: A reflection of pathophysiological cardiac changes

“…In diverse cardiac diseases, delayed conduction can be caused by prolonged and nonconsistent depolarization, in part due to left-atrial enlargement [6]. Wave prolongation can reflect increased ventricular enddiastolic pressure, and may even occur prior to ECG changes (ST depression) in coronary heart disease [35]. This is probably due to increased duration of the left atrial conduction component, as a result of stretching of its wall, secondary to increased left-atrial pressure [35].…”

Induction of Atrial Depolarization Abnormality during Dipyridamole Stress Imaging: A Cautionary Note

“…The significance of abnormal atrial depolarization, typified by widening P-wave duration during graded exercise, has been demonstrated [3,10,11,12]. Pandya et al [3] demonstrated a minute-by-minute exercise-induced increase in P-wave duration among patients with coronary artery disease and concluded that such P-wave widening could occur earlier than ST-segment deviation during exercise tests.…”

“…Pandya et al [3] demonstrated a minute-by-minute exercise-induced increase in P-wave duration among patients with coronary artery disease and concluded that such P-wave widening could occur earlier than ST-segment deviation during exercise tests. Our observations in hypertensive patients without atrioventricular valvular heart disease have also consistently delineated the association of incremental P-wave widening with certain exercise parameters, namely the Duke prognostic treadmill score [10].…”

“…While P-wave widening on the 12-lead electrocardiogram (ECG), denoting abnormal atrial depolarization [2], has been shown to be associated with myocardial ischemia during graded exercise [3], its true significance during dipyridamole stress imaging remains questionable given the potential direct as well as indirect effects of dipyridamole on the atria [4,5,6,7]. We present 5 comparable cases of dipyridamole stress imaging that revealed serial P-wave duration increase during administration of dipyridamole with subsequent resolution on the ECG.…”