Miller Ethan, Cadestin Marjorie, Patel Parita
Internal Medicine, Cooper Medical School of Rowan University, Camden, USA.
Internal Medicine, Cooper University Hospital, Camden, USA.
Cureus. 2025 Apr 3;17(4):e81646. doi: 10.7759/cureus.81646. eCollection 2025 Apr.
Mixed apical hypertrophic cardiomyopathy (MAHCM) is a rare variant of hypertrophic cardiomyopathy characterized by hypertrophy of the left ventricular (LV) apex with septal involvement, increasing the risk of left ventricular outflow tract (LVOT) obstruction, mid-ventricular obstruction, and adverse cardiovascular events such as syncope and sudden cardiac death. We describe an 84-year-old female with a history of hypertension and hyperlipidemia who presented with a syncopal episode preceded by dizziness, blurred vision, and diaphoresis, with a history of poor oral intake and weight loss. She was hemodynamically stable but exhibited orthostatic changes, and laboratory findings revealed acute kidney injury (AKI) suggesting hypovolemia. Electrocardiogram (ECG) showed normal sinus rhythm with left ventricular hypertrophy and repolarization abnormalities, while transthoracic echocardiography (TTE) revealed a hyperdynamic left ventricular ejection fraction (LVEF) of 75%, LV apical hypertrophy with septal involvement, mild systolic anterior motion of the mitral valve leaflet with trace mitral regurgitation, and diastolic dysfunction. The measured LVOT diameter, E/A ratio, E/E' ratio, and septal E' velocity per TTE indicated LVOT obstruction and diastolic dysfunction. The patient was treated with intravenous fluids for hypovolemia and initiated on carvedilol, leading to symptom resolution. Her clinical presentation, ECG findings, and echocardiographic parameters were suggestive of MAHCM, though differentiation from hypertensive heart disease remained a consideration. This case highlights the role of dehydration-induced hypovolemia in precipitating syncope in patients with MAHCM and underscores the importance of recognizing MAHCM in patients presenting with unexplained syncope. Early identification and management are critical in preventing complications such as arrhythmias and sudden cardiac death. Given the demographic variability and under-recognized nature of MAHCM, clinicians should maintain a high index of suspicion in elderly patients with hypertension who exhibit syncope, particularly in the setting of hypovolemia.
混合型心尖肥厚型心肌病（MAHCM）是肥厚型心肌病的一种罕见变异类型，其特征为左心室（LV）心尖肥厚并累及室间隔，增加了左心室流出道（LVOT）梗阻、心室中部梗阻以及诸如晕厥和心源性猝死等不良心血管事件的风险。我们描述了一位84岁的女性，有高血压和高脂血症病史，出现了一次晕厥发作，发作前有头晕、视力模糊和出汗症状，还有口服摄入量减少和体重减轻的病史。她血流动力学稳定，但存在体位性变化，实验室检查结果显示急性肾损伤（AKI）提示血容量不足。心电图（ECG）显示正常窦性心律，伴有左心室肥厚和复极异常，而经胸超声心动图（TTE）显示左心室射血分数（LVEF）为75%，呈高动力状态，LV心尖肥厚并累及室间隔，二尖瓣叶轻度收缩期前向运动伴微量二尖瓣反流，以及舒张功能障碍。TTE测量的LVOT直径、E/A比值、E/E'比值和室间隔E'速度表明存在LVOT梗阻和舒张功能障碍。该患者因血容量不足接受了静脉补液治疗，并开始使用卡维地洛，症状得以缓解。她的临床表现、ECG结果和超声心动图参数提示为MAHCM，不过仍需考虑与高血压性心脏病相鉴别。该病例突出了脱水引起的血容量不足在MAHCM患者晕厥发作中的作用，并强调了在不明原因晕厥患者中识别MAHCM的重要性。早期识别和管理对于预防心律失常和心源性猝死等并发症至关重要。鉴于MAHCM的人群差异和未被充分认识的特点，临床医生应对出现晕厥的老年高血压患者保持高度怀疑，尤其是在血容量不足的情况下。
