Apical hypertrophic cardiomyopathy (HC) is commonly regarded as a relatively benign condition of young to middle-aged Japanese men. Apical HC in a predominantly Caucasian population is not well characterized. The cardiovascular characteristics, morbidity, and mortality of a series of elderly, predominantly Caucasian subjects with apical HC are described. Thirty-two consecutive patients with apical HC (mean age 71 years, 15 men) were identified from a teaching hospital without a specialized HC clinic. Twenty-three subjects were Caucasian, 8 were Asian, and none Japanese. Twenty-two patients had coexistent hypertension. Six patients had documented late evolution of apical HC on electrocardiography and echocardiography up to 5 years after previous documented normal left ventricular morphology on echocardiography. The diagnosis of apical HC was initially missed in 7 patients because of inadequate image quality of the left ventricular apex and a lack of awareness of the condition. The correct diagnosis was assigned to all 7 patients after repeat echocardiography. Six of 13 patients who underwent coronary angiography had associated coronary artery fistulae. One patient required an implantable defibrillator for exertional syncope. Ten of the patients developed atrial fibrillation, 6 of whom had complicating thromboembolic events. Of the 6 deaths in the cohort, 2 followed atrial fibrillation–related hemiplegic strokes, and 2 followed progressive heart failure. In conclusion, apical HC in a teaching hospital without a specialized HC clinic and in a predominantly Caucasian population is a disease of the elderly. Documented late morphologic evolution is not uncommon, with a high incidence of coronary fistulae and morbid atrial fibrillation.
Apical hypertrophic cardiomyopathy (HC) was first described by Sakamoto et al and Yamaguchi et al in Japanese subjects. This variant of HC typically manifests with giant negative T waves on electrocardiography and a spadelike ventricle on contrast ventriculography, echocardiography, magnetic resonance imaging, or computed tomography. Inadequate image quality of the ventricular apex and a lack of awareness of the condition can lead to misdiagnosis. Apical HC accounts for 25% of all cases of HC in Japan, whereas in non-Japanese populations, it represents only 1% to 2% of cases. In middle-aged adults, apical HC is a benign condition, with reported overall survival of 95% at 15 years. The most common cardiac complications include atrial fibrillation, occurring in 12%. Most published data are derived from institutions with specialized HC clinics, and the clinical characteristics and prognoses of elderly patients with apical HC are unclear. One Japanese case series of apical HC suggests that elderly patients have a high incidence of heart failure, sudden cardiac death, and stroke associated with atrial fibrillation. We present a series of 32 patients with this condition and identify apical HC in predominantly Caucasian elderly patients as an important condition that is commonly associated with late morphologic evolution, coronary fistulae, and morbid atrial fibrillation.
Methods
Over a 5-year period from 2003 to 2008, 32 consecutive patients with apical HC were retrospectively identified in the cardiology department of a teaching hospital without a specialized HC clinic. The study was approved by the Human Ethics Committee of the Central Sydney Area Health Service (Concord Hospital Division). Presenting symptoms and associated clinical features were characterized, and cardiovascular morbidity and mortality were determined on follow-up. Electrocardiograms were examined for thepresence of left ventricular (LV) hypertrophy and “giant” negative T waves, defined as a voltage of negative T wave ≥1 mV (≥10 mm) in any of the leads. All diagnoses of apical HC required technically adequate apical views during transthoracic echocardiography. Studies were performed with Vingmed Vivid 5 and 7 units (GE Medical Systems, Milwaukee, Wisconsin) with tissue-harmonic capabilities. Studies were reviewed by 2 experienced echocardiographers to establish the presence or absence of apical HC. Apical HC was identified as asymmetric LV hypertrophy confined to the LV apex, where the apex was the thickest ventricular segment and when significant hypertrophy was absent from other segments measured in the parasternal long-axis view. We previously reported a case series of adults with noncompaction cardiomyopathy affecting the LV apex, and care was taken to exclude such patients. Other conditions that could affect the morphologic appearance of the LV apex such as apical thrombus were also excluded.
Results
The clinical characteristics of our patients are listed in Table 1 . Our cohort was elderly, with a mean age of 71 years. The mean follow-up of the patients was 4 ± 3 years (range 1 to 26), and 2 patients were lost to follow-up. The patients were unrelated apart from 2 who were related as father and daughter. Twenty-two patients had hypertension at the time of presentation. There were 6 deaths in the cohort, including 2 after atrial fibrillation–related hemiplegic strokes and 2 from progressive heart failure. Apical HC was confined to the apical region in 24 patients and extended from the apex toward the lateral wall in 8 patients. None of the cohort had HC involving the ventricular septum. The mean maximal apex hypertrophy was 17 ± 2 mm. The mean left atrial diameter was 44 ± 9 mm. No patients had evidence of LV outflow obstruction. Five patients had moderate mitral regurgitation on echocardiography, and 2 patients had tricuspid regurgitation of moderate severity.
| Patient | Age/Gender | Nationality | History of HTN | ECG Results | Distribution of Apical HC | Unusual Features of Apical HC | Clinical Outcomes |
|---|---|---|---|---|---|---|---|
| 1 | 36/F | Korean | No | SR | Periapical | Coronary artery–pulmonary artery fistula ⁎ | |
| 2 | 43/F | Caucasian | No | SR | Periapical | ||
| 3 | 53/M | Caucasian | Yes | SR | Periapical | Coronary artery–pulmonary artery fistula | |
| 4 | 57/M | Malaysian | Yes | AF, GNT | Periapical | ADF | |
| 5 | 58/F | Chinese | No | SR, GNT | Apex-lateral | ADF, coronary artery–LV fistula | |
| 6 | 61/F | Sri-Lankan | Yes | SR, GNT | Periapical | 3-vessel disease | |
| 7 | 61/M | Caucasian | Yes | SR, GNT | Periapical | Coronary artery–LV fistula | |
| 8 | 63/M | Caucasian | Yes | SR, GNT | Apex-lateral | DL | ICD for VT |
| 9 | 67/F | Caucasian | Yes | SR | Periapical | ||
| 10 | 67/M | Caucasian | No | SR | Periapical | ||
| 11 | 68/M | Korean | No | SR, GNT | Periapical | ||
| 12 | 68/M | Greek | Yes | AF | Periapical | CVA, death | |
| 13 | 69/M | Caucasian | No | SR, GNT | Periapical | ADF | |
| 14 | 71/F | Caucasian | No | AF | Periapical | ||
| 15 | 73/M | Italian | No | SR, GNT | Periapical | ||
| 16 | 75/F | Caucasian | No | SR | Periapical | Coronary artery–LV fistula | |
| 17 | 75/F | Italian | Yes | SR, GNT | Periapical | Coronary artery–LV fistula | Death |
| 18 | 75/F | Caucasian | Yes | SR | Periapical | ||
| 19 | 75/M | Italian | Yes | AF, GNT | Periapical | DL | TIA |
| 20 | 76/M | Italian | No | AF, RBBB | Apex-lateral | DL | |
| 21 | 78/M | Chinese | Yes | SR | Periapical | ADF, AA | |
| 22 | 78/F | Chinese | No | AF, GNT | Periapical | CVA, death | |
| 23 | 78/F | Caucasian | Yes | SR | Apex-lateral | ||
| 24 | 80/M | Caucasian | Yes | SR | Periapical | ||
| 25 | 80/M | Caucasian | Yes | AF, GNT | Periapical | DL | CVA |
| 26 | 81/M | Caucasian | Yes | AF | Periapical | ADF | CHF |
| 27 | 82/F | Caucasian | Yes | SR | Apex-lateral | ||
| 28 | 83/F | Polish | Yes | SR | Periapical | AA, ADF | |
| 29 | 83/M | Greek | Yes | AF, GNT | Apex-lateral | DL | CVA, PPM, PE, death |
| 30 | 87/F | Korean | Yes | SR, GNT | Apex-lateral | ADF | |
| 31 | 88/F | Caucasian | Yes | AF, GNT | Apex-lateral | TIA, CHF, death | |
| 32 | 91/F | Caucasian | Yes | SR | Periapical | AA, DL | CHF, death |
⁎ Apical HC diagnosed 8 years after the diagnosis of the coronary artery–pulmonary artery fistula.
Arrhythmias were highly prevalent and clinically important in this population. One patient presented with exertional syncope, giant T waves on electrocardiography, and without apical HC on initial echocardiography. This patient required an implantable defibrillator for inducible ventricular tachycardia on an electrophysiologic study and developed apical HC on echocardiography 2 years later. One patient developed sick sinus syndrome and required a permanent pacemaker. Ten patients had atrial fibrillation, 2 of whom had atrial fibrillation for some years before development of apical HC. Six of these 10 patients had hypertension. One patient developed LV failure after developing atrial fibrillation. It is notable that 6 of the 10 patients with atrial fibrillation had complicating thromboembolic events. One patient had pulmonary thromboembolism, and 6 patients had cerebral embolic events. Two patients had fatal hemiplegic strokes. Four of 6 patients had international normalized ratios of 2 to 3 at the time of stroke. The other 2 patients had previous bleeding complications on oral anticoagulation and had their strokes while receiving aspirin therapy. All 6 patients had normal results on carotid Doppler studies. No patients underwent transesophageal echocardiography or magnetic resonance imaging.
Six of the 32 patients had documented late evolution of apical HC on echocardiography, at the ages of 63, 75, 76, 80, 83, and 91 years ( Figure 1 ). Retrospective analysis of all 6 patients’ initial echocardiograms confirmed their normal LV morphology at first presentation. Five of these 6 patients had preexisting hypertension. In 3 of these patients, electrocardiographic results on presentation were abnormal, with deep T-wave inversion without evidence of apical HC on echocardiography. Echocardiographic changes of apical HC developed from 2 to 5 years later, at the ages of 63, 75, and 91 years. The other 3 patients had normal electrocardiographic and echocardiographic results at earlier time points but developed echocardiographic apical HC at the ages of 76, 80, and 83 years. Other patients in the cohort had no previous electrocardiography or echocardiography at the time of diagnosis, so apical HC could either have evolved late in life or simply have presented at an elderly age.
