Non-Hypertensive Patients with Prolonged P-Wave Indices Have Higher Blood Pressure Response to Exercise Stress Test

Abstract

Background/Objectives: Hypertension during exercise has been linked to future hypertension. Prolonged P-wave indices (PWI) has also been associated with prehypertension. We aim to compare exercise stress test parameters in non-hypertensives with normal and prolonged PWI. Methods: Non-hypertensive patients above 18 years without known heart disease and negative ECG stress test were studied. 12-lead ECG at a paper speed of 25 mm/s and 1 mV/cm were recorded. An electronic caliper and magnifier were used to measure PWI. Patients were classified into normal or prolonged P-wave duration and dispersion. Stress test parameters such as systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) at rest, peak, and recovery; target heart rate achieved; exercise duration; METs; and rate pressure products were recorded. Results: 76 patients were eligible with mean age of 43.77±12.16. 46% were male. 36% and 47% had prolonged P-wave duration and dispersion respectively. Patients with prolonged P-wave duration have higher peak DBP than those with normal duration (91.54±10.07 versus 84.69±9.60, P=0.006). Recovery SBP and DBP were also significantly higher. Among patients with prolonged P wave dispersion, recovery SBP and DBP were significantly higher compared with normal subjects (P<0.05). Conclusion: Prolonged PWI were associated with higher blood pressure response to exercise stress test. Further investigations may provide more conclusive evidences in the role of PWI as novel markers of future hypertension.