Influence of heart rate on Doppler aortic regurgitant velocity curve: Clinical role of heart rate correction of regurgitant pressure half-time

Because it was recently suggested that pressure half-time (PHT) of aortic r egurgitant velocity curve is influenced by heart rate (HR) We retrospective ly analyzed 76 patients with aortic regurgitation (AR) to determine whether PHT independently correlates with HR and whether HR correction of PHT can be clinically useful. PHT correlated significantly (P < 0.001) with color D oppler relative regurgitant jet height (r = -0.62), with angiographic gradi ng (r = -0.65), and with HR (r = -0.54); such correlations were confirmed b y multivariate analysis. Tachycardia influences aortic velocity curve more than bradycardia, and this effect is more evident in patients with milder r egurgitation. Two methods of HR correction of PHT were tested: relative PHT (PHT/diastolic time x 100) and corrected PHT (PHT/root RR): only corrected PHT was independently related to both relative regurgitant jet height and angiographic grading (P < 0.001). HR correction of PHT by corrected PHT was of limited clinical usefulness: in fact, in the entire study population, t he accuracy of the usual cutoff (< 300 msec) in detecting relevant AR was n ot improved by corrected PHT. However, in patients with higher HR (greater than or equal to 85 beats/min), in whom the effect of HR on aortic velocity curve appeared to be greater, corrected PHT teas superior to PHT because t he cutoff value of < 300 msec showed a good specificity (100%), a moderate sensitivity (66%), and a good accuracy (80%) in detecting relevant AR. Corr ected PHT can be useful to confirm AR severity when a short PHT is observed in tachycardic patients.