RESUMO
Because it was recently suggested that pressure half-time (PHT) of aortic regurgitant velocity curve is influenced by heart rate (HR), we retrospectively 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 Doppler relative regurgitant jet height (r = -0.62), with angiographic grading (r = -0.65), and with HR (r = -0.54); such correlations were confirmed by multivariate analysis. Tachycardia influences aortic velocity curve more than bradycardia, and this effect is more evident in patients with milder regurgitation. Two methods of HR correction of PHT were tested: relative PHT (PHT/diastolic time x 100) and corrected PHT (PHT/ radicalRR): 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, the accuracy of the usual cutoff (< 300 msec) in detecting relevant AR was not improved by corrected PHT. However, in patients with higher HR (>/= 85 beats/min), in whom the effect of HR on aortic velocity curve appeared to be greater, corrected PHT was superior to PHT because the cutoff value of < 300 msec showed a good specificity (100%), a moderate sensitivity (66%), and a good accuracy (80%) in detecting relevant AR. Corrected PHT can be useful to confirm AR severity when a short PHT is observed in tachycardic patients.
