Mayet J, Shahi M, McGrath K, Poulter N R, Sever P S, Foale R A, Thom S A
Peart-Rose Clinic, St Mary's Hospital, London, UK.
Hypertension. 1996 Nov;28(5):791-6. doi: 10.1161/01.hyp.28.5.791.
The interlead variation in QT length on a standard electrocardiograph reflects regional repolarization differences in the heart. To investigate the association between this interlead variation (QT dispersion) and left ventricular hypertrophy, we subjected 100 untreated subjects to 12-lead electrocardiography and echocardiography. Additionally, 24 previously untreated subjects underwent a 6-month treatment study with ramipril and felodipine. In the cross-sectional part of the study, QT dispersion corrected for heart rate (QTc dispersion) was significantly correlated with left ventricular mass index (r = .30, P < .01), systolic pressure (r = .30, P < .01), the ratio of peak flow velocity of the early filling wave to peak flow velocity of the atrial wave (E/A ratio) (r = -.22, P = .02), isovolumic relaxation time (r = .31, P < .01), and age (r = .21, P < .04). In the treatment part of the study, lead-adjusted QTc dispersion decreased from 24 to 19 milliseconds after treatment, and after a subsequent 2 weeks of drug washout remained at 19 milliseconds (P < .01). The changes in left ventricular mass index at these stages were 144, 121, and 124 g/m2 (P < .01). Systolic pressure decreased from 175 to 144 mm Hg and increased again to 164 mm Hg after drug washout (P < .01). The E/A ratio (0.97, 1.02, and 1.02; P = 69) and isovolumic relaxation time (111, 112, and 112; P = .97) remained unchanged through the three assessment points. In conclusion, QT dispersion is increased in association with an increased left ventricular mass index in hypertensive individuals. Antihypertensive therapy with ramipril and felodipine reduced both parameters. If an increased QT dispersion is a predictor of sudden death in this group of individuals, then the importance of its reduction is evident.
标准心电图上导联间QT间期的变化反映了心脏区域复极的差异。为了研究这种导联间变化（QT离散度）与左心室肥厚之间的关联，我们对100名未经治疗的受试者进行了12导联心电图和超声心动图检查。此外，24名先前未经治疗的受试者接受了为期6个月的雷米普利和非洛地平治疗研究。在研究的横断面部分，校正心率后的QT离散度（QTc离散度）与左心室质量指数显著相关（r = 0.30，P < 0.01）、收缩压（r = 0.30，P < 0.01）、舒张早期峰值流速与心房波峰值流速之比（E/A比值）（r = -0.22，P = 0.02）、等容舒张时间（r = 0.31，P < 0.01）和年龄（r = 0.21，P < 0.04）。在研究的治疗部分，治疗后导联校正的QTc离散度从24毫秒降至19毫秒，随后停药2周后仍保持在19毫秒（P < 0.01）。这些阶段左心室质量指数的变化分别为144、121和124 g/m²（P < 0.01）。收缩压从175毫米汞柱降至144毫米汞柱，停药后又升至164毫米汞柱（P < 0.01）。E/A比值（0.97、1.02和1.02；P = 0.69）和等容舒张时间（111、112和112；P = 0.97）在三个评估点保持不变。总之，高血压个体中QT离散度随左心室质量指数增加而升高。雷米普利和非洛地平的抗高血压治疗降低了这两个参数。如果QT离散度增加是该组个体猝死的预测指标，那么降低它的重要性就很明显了。
