Hypertrophic Cardiomyopathy Center, Cleveland Clinic, Cleveland, Ohio.
Hypertrophic Cardiomyopathy Center, Cleveland Clinic, Cleveland, Ohio.
Am J Cardiol. 2024 Dec 1;232:34-40. doi: 10.1016/j.amjcard.2024.09.017. Epub 2024 Sep 20.
Diastolic dysfunction plays a major role in precipitating congestive heart failure in patients with hypertrophic cardiomyopathy (HCM). In many such patients, symptoms are unmasked only during exercise because left ventricular (LV) filling pressure is normal at rest but increase with exercise. We sought to establish whether abnormal postexercise diastolic parameters are associated with reduced exercise capacity in patients with HCM. We examined 590 patients with asymptomatic/minimally symptomatic HCM (age 54 ± 14 years, 57% men, body mass index 30 ± 6 kg/m, 84% on β blockers) with HCM by 2-dimensional and Doppler echocardiography at rest and after maximal treadmill exercise echocardiography (TSE). A complete echocardiogram (including LV ejection fraction, LV thickness, LV outflow tract [LVOT] gradient, degree of mitral regurgitation) was recorded. Diastolic parameters (septal and lateral [e'] velocities of the mitral annulus, peak early [E] and late [A] mitral inflow velocity, E/A ratio, E/e', right ventricular systolic pressure [RVSP], and left atrial volume index) were recorded at rest and after TSE. Exercise functional capacity was recorded and divided into <85% or >85% of age-gender predicted metabolic equivalents (AGP-METs). After maximal exercise, 32% patients had at least moderate mitral regurgitation, mean LVOT gradient was 61 ± 59 mm Hg, E/A ratio was 1.2 ± 1.0, average E/e' ratio 12.9 ± 1.0, and peak RVSP was 36 ± 15 mm Hg. Only 42% of patients achieved >85% of AGP-METs; the mean METs was 7 ± 3. On multivariable logistic regression analysis, higher body mass index (odds ratio [OR] 1.05), β-blocker use (OR 2.58), higher left atrial volume index (OR 1.02), higher peak stress LVOT gradient (LVOTG) (OR 1.06), peak stress E/e' (OR 1.04), and higher RVSP (OR 1.03) were independently associated with <85% AGP-METs achieved (all p <0.05). In conclusion, in patients with asymptomatic/minimally symptomatic HCM who underwent TSE, there is a significant and independent association between abnormal diastolic response to exercise and reduced exercise capacity in HCM. Incorporating diastolic parameters during stress echocardiography could provide incremental diagnostic utility in deciphering the exact etiology of dyspnea in such patients.
舒张功能障碍在肥厚型心肌病（HCM）患者心力衰竭的发生中起主要作用。在许多此类患者中，症状仅在运动时才显现出来，因为左心室（LV）充盈压在休息时正常，但在运动时增加。我们试图确定 HCM 患者异常的运动后舒张参数是否与运动能力下降有关。我们通过二维和多普勒超声心动图检查了 590 名无症状/轻度症状的 HCM 患者（年龄 54 ± 14 岁，57%为男性，体重指数 30 ± 6 kg/m，84%服用β受体阻滞剂），并在最大平板运动超声心动图（TSE）后进行了检查。记录了完整的超声心动图（包括 LV 射血分数、LV 厚度、LV 流出道[LVOT]梯度、二尖瓣反流程度）。在 TSE 前后记录舒张参数（二尖瓣环间隔和侧壁[e']速度、早期[E]和晚期[A]二尖瓣流入速度、E/A 比值、E/e'、右心室收缩压[RVSP]和左心房容积指数）。记录运动功能能力并分为<85%或>85%年龄性别预测代谢当量（AGP-METs）。最大运动后，32%的患者至少有中度二尖瓣反流，平均 LVOT 梯度为 61 ± 59 mmHg，E/A 比值为 1.2 ± 1.0，平均 E/e'比值为 12.9 ± 1.0，峰值 RVSP 为 36 ± 15 mmHg。只有 42%的患者达到>85%的 AGP-METs；平均 METs 为 7 ± 3。多变量逻辑回归分析显示，较高的体重指数（比值比[OR] 1.05）、β受体阻滞剂的使用（OR 2.58）、较高的左心房容积指数（OR 1.02）、较高的峰值应激 LVOTG（OR 1.06）、峰值应激 E/e'（OR 1.04）和较高的 RVSP（OR 1.03）与<85%的 AGP-METs 呈独立相关（均 p <0.05）。总之，在接受 TSE 的无症状/轻度症状的 HCM 患者中，运动后舒张反应异常与 HCM 运动能力下降之间存在显著的独立相关性。在应激超声心动图中纳入舒张参数可能会提供额外的诊断效用，有助于解析此类患者呼吸困难的确切病因。
