Isolated left ventricular noncompaction (IVNC) is a rare congenital cardiomyopathy resulting from an arrest in normal endomyocardial embryogenesis. Clinical presentations of IVNC include systolic and diastolic dysfunction, systemic embolism and ventricular arrhythmias. In recent years there has been an increasing awareness of this anomaly; however, especially in elderly, clinical characterization and natural course of IVNC are still in question. In this case, we report a case of a 78-year-old patient with the diagnosis of IVNC with preserved left ventricular (LV) systolic function. To the best of our knowledge, this is the oldest IVNC case with preserved LV systolic function in the literature.
Isolated left ventricular noncompaction (IVNC) is a rare and unclassified congenital cardiomyopathy1 that is thought to be related to arrest of myocardial development, resulting in persistence of multiple prominent ventricular trabeculations and deep intertrabecular recesses.2 IVNC was described initially in the pediatric population,2 but recent reports have identified it in the adult population.3–5 In recent years there has been an increasing awareness of this anomaly; however, especially in elderly, clinical characterization and long-term prognosis of IVNC are still in question. We report a case of IVNC in an elderly woman, who has preserved left ventricular (LV) systolic function.
A 78-year-old woman admitted to our hospital with the complaints of palpitation and exertional dyspnea. Her medical history was remarkable for an echocardiographic diagnosis of apical hypertrophic cardiomyopathy with normal LV systolic function which had been detected 5 years ago. Her blood pressure was 110/75mmHg and heart rate was 80beats/min. Cardiac auscultation was normal except for a fourth heart sound. The remainder of the physical examination findings was unremarkable. The electrocardiogram showed sinus rhythm, normal QSR duration, and LV hypertrophy with repolarization changes. Chest X-ray showed a normal cardiothoracic ratio. Non-sustained ventricular tachycardia was noted in Holter monitorization. Two-dimensional transthoracic echocardiography (TTE) demonstrated that LV dimensions were normal (end-diastolic diameter of 49mm) with a lower limit of normal systolic function (left ventricular ejection fraction (LVEF) was 50%). Characteristic, prominent numerous trabeculations in the LV apex and inferior, posterior, and lateral mid-ventricular wall were noticed. Deep intertrabecular spaces communicating with the main LV cavity were also evident on both two-dimensional echocardiogram and colour Doppler imaging (Figs. 1 and 2). Maximum wall thickness of the LV was observed to be 27mm in the apex with a noncompacted/compacted layers ratio of 4.2. Because all these echocardiographic findings were found to be consistent with previously reported criteria of IVNC,4 the diagnosis of IVNC was established. Additionally, E/A wave ratio in mitral inflow showed impaired relaxation pattern. Left and right heart catheterization and coronary angiography were performed and revealed that systolic pulmonary artery pressure was 30mmHg and LV end-diastolic pressure was 15mmHg. Coronary arteries were normal. The left ventriculogram showed mild hypokinesia with apex and posterolateral wall, sponge-like appearance of the noncompacted ventricular wall during the diastolic phase and marked retention of the contrast medium in the intertrabecular recesses during the systolic phase (Fig. 3). The patient was started on aspirin and carvedilol and was discharged. Her condition has remained stable over the past 2 years without the evidence of heart failure and her last echocardiogram showed preserved LV systolic function with same LVEF.
Apical long-axis view of the left ventricle showing the typical prominent trabeculations in the left ventricular apex with deep intertrabecular recesses (A, two-dimensional echocardiogram, B, colour Doppler imaging).
Two-dimensional echocardiogram in parasternal short-axis view at the mid-ventricular level showing prominent, numerous trabeculations in the left ventricular inferior, posterior, and lateral wall with deep intertrabecular recesses (A). Colour Doppler echocardiogram demonstrating flow within deep intertrabecular recesses in continuity with the left ventricular cavity (B).
Left ventricular angiogram (left anterior oblique projection) demonstrating an abnormally prominent trabecular zone and deep intertrabecular recesses (arrows) in the inferoposterior wall.
IVNC has been categorized as an unclassified cardiomyopathy by the World Health Organization in the recently published report on definition and classification of cardiomyopathies.1 It is a result of an arrest in myocardial morphogenesis and is characterized by excessively prominent trabeculations in a ventricular wall segments and deep intertrabecular recesses.2 Although true prevalence of this rare cardiomyopathy is unknown, it has been reported to be 0.014% in the largest adult series4 and 0.14% in the largest pediatric series,5 and the actual prevalence is thought to be even higher.
Three types of clinical presentations have been described in patients with IVNC: (1) systolic and diastolic dysfunction, (2) ventricular arrhythmias, and (3) systemic embolisation.2–4 Findings vary among patients, ranging from asymptomatic left ventricular dysfunction to severe, disabling congestive heart failure. Diastolic dysfunction probably results from a combination of an abnormal ventricular relaxation and restriction to ventricular filling caused by the abundance of intracavitary trabeculae. The cause of progressive myocardial failure has not been yet elucidated. Relative chronic myocardial ischemia caused by mismatch of blood demand and supply to multiple prominent trabeculae is a possible mechanism of progressive systolic dysfunction.2 Moreover, coronary microcirculatory dysfunction with a decreased coronary flow reserve has been proposed as a mechanism of IVNC associated myocardial failure by Jenni et al.6
There are conflicting data on IVNC prognosis. In initial reports, IVNC was defined as a disease of high mortality associated with heart failure, ventricular arrhythmias, and sudden death.2–4 Preliminary data suggest that although patients with IVNC who are asymptomatic at presentation have a longer clinical course, the majority of these individuals do go on to develop LV dysfunction.7 Over two-thirds of the patients in the largest series with IVNC had symptomatic heart failure.4 Nevertheless, reports of IVNC cases with better prognosis have recently been published as in our case5,7 and the natural course of this disease is not fully known.
In the initial case series of IVNC, the median age at diagnosis was 7 years.2 Subsequent case reports have described this finding in adults, including the elderly.3–5 In the largest adult series of IVNC, the median age was 40 years, and upper limit of age was 71 years.4 Takashima et al. recently reported the oldest IVNC patient who had been 83-year-old and presented with overt heart failure due to LV dilation and diffuse hypokinesia.8 To the best of our knowledge, our case represents the oldest IVNC patient with preserved LV systolic function.