CardioExchange Archive

A 21-year-old Division I college football player presented with palpitations that had started during athletic practice. He was referred to a cardiologist for further evaluation.

Vital signs and physical exam were normal. An EKG showed prominent R waves, inverted T waves in leads V1–V2, along with a biphasic T wave in lead V3. QRS axis and QTc interval were normal.

A transthoracic echocardiogram raised concerns about possible left-ventricular noncompaction.

LV systolic function was found to completely normal. However, the ratio of thick, noncompacted myocardium to thin, compacted myocardium was 1.7 in end-systole. (Jenni criteria include the presence of a maximum ratio of noncompacted-to-compacted myocardium >2 to 1 at end-systole in the parasternal short-axis view.)

An MRI was performed to confirm the diagnosis.

A detailed review showed mild biventricular enlargement with a ratio of thick, noncompacted to thin, compacted myocardium of 2.0. (The best distinguishing feature for LV noncompaction was a maximum ratio in diastole of noncompacted-to-compacted myocardial thickness of >2.3 to 1, as assessed in three long-axis views.)

The patient has a college football scholarship and dreams of becoming an NFL player.

Questions:
1. Would you advise the patient to continue playing competitive football?

2. Would you perform any additional tests? How would the test results affect your decision about whether to let him play?

Response:

James Fang, MD

January 12, 2012

This young man with palpitations has modest EKG abnormalities, as well as echo and MRI findings that suggest LV noncompaction (LVNC) — an uncommon cardiomyopathy due to congenital lack of endocardial compaction of the spongiform myocardium. The patient requires more investigation before concluding that he has LVNC. Exercise testing and Holter monitoring should be performed. In addition, a careful family history should be taken, given that up to half of all LVNC cases are reported to be familial. The inheritance pattern of LVNC appears to be X-linked, which should be considered in obtaining the family history.

Important aspects of the imaging diagnosis include the ability to see flow within the trabeculae of the noncompacted endocardium and localization of the noncompaction to the inferolateral and apical regions. The diagnosis generally requires a clinical picture of systolic heart failure, thromboembolic phenomena, arrhythmia, and/or familial inheritance.

If systolic and diastolic function are completely normal in the setting of normal exercise echocardiography and Holter results, the diagnosis of LVNC would be, at best, possible. However, the patient should be followed for the development of symptoms. Although sudden death from arrhythmias is a well-known complication of LVNC, it is an unusual first manifestation.

The diagnostic criteria for LVNC continue to evolve. The criteria differ depending upon the modality used to establish the diagnosis. Specifically, the diagnosis is made (1) from the systolic ratio of spongiform endocardium to epicardium using echocardiography but (2) from the diastolic ratio using MRI. Furthermore, the imaging quality of MRI has become so good that “hypertrabeculation” in many instances represents a normal variant rather than a pathologic finding. Some have expressed concerns that, in the absence of a suggestive clinical picture (e.g., symptoms, family history), a diagnosis of LVNC should not rest entirely on the imaging findings. In fact, both underdiagnosis and overdiagnosis likely occur in clinical practice.

Given these considerations, the patient should refrain from athletic activity until the above evaluation is completed. I would ultimately advise against participation in vigorous athletics in the case of a positive family history, abnormal results on the tests I have recommended, or development of further symptoms.

Follow-Up:

Tariq Ahmad, MD, MPH

January 19, 2012

The patient underwent a cardiac catheterization that revealed normal coronary arteries. During a manual 1-minute-stage exercise protocol, he exercised for 9 minutes 35 seconds and achieved a peak workload of 17.9 METs. Peak oxygen consumption was 54 mL/kg/minute (114% of predicted). No arrhythmias were noted during the study.

During an electrophysiologic study to risk-stratify the patient for sudden cardiac death, ventricular extra stimulus testing was performed using pacing at both the right-ventricular outflow tract and the right-ventricular apex, with up to 3 extra stimuli. Ventricular tachycardia (nonsustained or sustained) could not be induced.

The patient was told to “sit out” this football season and, if he remained asymptomatic, resume playing next year. He did so, without any further symptoms.

Interestingly, transthoracic echocardiography, performed after the patient reduced his activity level, showed improvement in trabeculations.