A 25-year-old Hispanic man presented to the emergency department with a complaint of three days of left-sided precordial chest pain. He described the pain as a constant 6/10 with pressure-like discomfort radiating to his left arm and the left side of his neck. He also experienced nausea, but denied any provocative or palliative factors. He said he had not experienced anything similar to this before.
He had no family history of heart disease, acute myocardial infarction, or sudden cardiac death. He admitted to a 1.5 pack-per-day smoking history and social alcohol use, but denied use of any illicit substances. The patient also reported a recent upper respiratory infection that had completely resolved.
The patient appeared pale, diaphoretic, and anxious. No murmurs or extra heart sounds were appreciated, and he had no chest wall tenderness, jugular venous distention, or peripheral edema. The remainder of his exam was unremarkable.
His electrocardiogram showed sinus rhythm at 66 beats per minute with diffuse T wave inversions and ST elevations greater than 1 mm in leads V1-V3. (Figure 1.) His chest radiograph was normal.
The cardiac catheterization team was activated for a presumed anterior wall MI based on his EKG findings and symptoms. The patient was placed on oxygen via nasal cannula, and labs, including cardiac enzymes, were drawn. He was given aspirin and sublingual nitroglycerin, and taken to the catheterization lab.
The patient underwent emergent left heart catheterization, ventriculography, and root aortography for presumed coronary artery disease and acute myocardial infarction. His left ventricle was found to be hypercontractile and mildly hypertrophied. Apical obliteration was present, and the apex was noted to have a spade-shape characteristic of hypertrophic apical cardiomyopathy. (Figure 2.) The coronary arteries were normal, and no aortic stenosis was present. Trace aortic insufficiency was present, however, and the aortic root was of normal caliber. The patient was diagnosed with apical hypertrophic cardiomyopathy, or Yamaguchi Syndrome.
Two hours post-cardiac catheterization, the patient was discharged home with instructions to follow up with the cardiologist for an outpatient echocardiogram and genetic testing. The patient was also instructed to abstain from sports and other athletic activity until cleared by cardiology.
The patient did not keep his appointments with cardiology, and returned to the ED twice with the same complaint of left-sided chest pain. The patient was seen by cardiology in the ED on both occasions, and MI was subsequently ruled out.
Hypertrophic cardiomyopathy (HCM) is a heterogeneous disease of the cardiac sarcomere with a variable clinical course that is dependent on several factors, including genetics, location, and degree of left ventricular outflow obstruction. (Circulation 1995;92:1680.)
Apical hypertrophic cardiomyopathy (ApHCM) is a relatively rare subtype of HCM (J Am Coll Cardiol 2002;39:638) in which the abnormality is confined to the apex of the left ventricle, causing a nonobstructive cardiomyopathy. (South Med J 2003;96:828.)
ApHCM has been described primarily in Japanese patients but manifests in other populations with significantly less frequency. (J Am Coll Cardiol 1990;15:91.) ApHCM constitutes up to 25 percent of cases of HCM in Japanese patients and only three percent in the rest of the population. (South Med J 2003;96:828.) This is likely how ApHCM came to be called Yamaguchi Syndrome, named for Sakamoto Yamaguchi, who first described the typical features of ApHCM. (J Am Coll Cardiol 2002;39:638.)
ApHCM most commonly presents in young male patients as angina (16%), atypical chest pain (14%), palpitations (10%), dyspnea (6%), or syncope/presyncope (6%). (J Am Coll Cardiol 2002;39:638.) A variety of mechanisms are thought to contribute to anginal symptoms, including imbalances between oxygen supply and demand as a consequence of hypertrophied myocardium with normal coronary arteries. (South Med J 2003;96:828.)
These patients have some characteristic findings, including giant T wave inversions on electrocardiogram, which are most prominent in V4, and a spade-shaped left ventricular cavity at end diastole seen on ventriculography. (J Am Coll Cardiol 2002;39:638.)
Evaluation for HCM patients typically includes a transthoracic Doppler echocardiogram to determine the location and extent of hypertrophy, systolic and diastolic function, degree of obstruction if present, atrial size, and valvular abnormalities. (Circulation 1995;92:1680.)
Occasionally, 2D echocardiogram will not provide adequate information, and the patient will require cardiac MRI, which has been found to provide better overall assessment of left ventricular hypertrophy in HCM patients. (J Am Coll Cardiol 2002;39:638; Circulation 1995;92:1680.)
Cardiac catheterization and angiography are generally reserved for cases with diagnostic uncertainty or in which myocardial infarction is suspected. (Circulation 1995;92:1680.)
Sudden cardiac death is the most common cause of death in HCM patients, but ApHCM is not associated with sudden cardiac death, and has a benign prognosis for cardiovascular mortality. (J Am Coll Cardiol 2002;39:638.) Approximately one-third of ApHCM patients go on to develop complications including MI, arrhythmias, and stroke. (J Am Coll Cardiol 2002;39:638.)
Several treatment options for HCM exist, including medical therapy with beta blockers, calcium channel blockers and antiarrhythmics, pacemakers, and a myectomy. (Circulation 1995;92:1680.) Treatment is generally based on patient symptoms and whether the patient has obstructive or nonobstructive disease. (J Am Coll Cardiol 2002;39:638.) A majority (75%) of patients with HCM have the nonobstructive type. It is important to note, however, that HCM is not a static disease manifestation. It can appear at any age, and increase or decrease dynamically throughout life. (JAMA 2002;287:1308.)