Klein H O, DiSegni E, Dean H, Beker B, Bakst A, Kaplinsky E
Department of Cardiology, Meir General Hospital, Sapir Medical Center, Kfar Saba, Israel.
Chest. 1988 Apr;93(4):814-20. doi: 10.1378/chest.93.4.814.
In a prospective study murmurs increased in intensity with carotid sinus pressure in 18 of 26 patients with hypertrophic obstructive cardiomyopathy (HOCM) (sensitivity, 69.2 percent for the 26 patients, 85.7 percent for the 21 patients in whom heart rate and blood pressure decreased with carotid sinus pressure). On the other hand, the murmur remained constant or decreased in all but one of 104 patients with valvular aortic stenosis, mitral insufficiency, hypertrophic nonobstructive cardiomyopathy, and systolic murmurs of miscellaneous origins (specificity, 99 percent; positive predictive value, 94.7 percent). Catheterization, indirect arterial pressure tracings, and echocardiographic studies indicated that carotid sinus pressure-induced bradycardia was associated with increased left ventricular outflow tract obstruction. The carotid sinus pressure-induced increase in the murmur is probably multifactorial: decreased aortic pressure and impedance; increased contractility immediately on sudden slowing of heart rate; further increase in obstruction as the mitral valve systolic anterior movement is enhanced; and delayed vasodilatation maintaining the obstruction even after return of heart rate to precarotid sinus pressure values. An increase in a systolic murmur with carotid sinus pressure is characteristic of HOCM.
在一项前瞻性研究中，26例肥厚型梗阻性心肌病（HOCM）患者中有18例的杂音强度随颈动脉窦按压而增强（对26例患者的敏感性为69.2%，对21例心率和血压随颈动脉窦按压而降低的患者的敏感性为85.7%）。另一方面，在104例患有瓣膜性主动脉狭窄、二尖瓣关闭不全、肥厚型非梗阻性心肌病以及其他原因引起的收缩期杂音的患者中，除1例之外，其余患者的杂音保持不变或减弱（特异性为99%；阳性预测值为94.7%）。心导管检查、间接动脉压描记以及超声心动图研究表明，颈动脉窦按压诱发的心动过缓与左心室流出道梗阻增加有关。颈动脉窦按压引起的杂音增强可能是多因素的：主动脉压力和阻抗降低；心率突然减慢后立即出现的心肌收缩力增强；随着二尖瓣收缩期前向运动增强，梗阻进一步加重；以及即使心率恢复到颈动脉窦按压前的值后，延迟的血管扩张仍维持梗阻状态。收缩期杂音随颈动脉窦按压而增强是HOCM的特征。
