ECG IMAGE OF THE MONTH Julia H. Indik, MD, PhD, Section Editor
T-wave Tease: Apical Hypertrophic Cardiomyopathy Lindsey H. Malik, DO, Gagan D. Singh, MD, Ezra A. Amsterdam, MD Division of Cardiovascular Medicine, Department of Internal Medicine, University of California Davis Medical Center, Sacramento.
PRESENTATION The T wave of the electrocardiogram (ECG) represents ventricular repolarization and is typically concordant with the vector of the QRS complex. Its direction and morphology are influenced by numerous physiologic and pathophysiologic factors.1 Myocardial ischemia is among the most common and important diagnoses that should be considered upon recognition of T-wave inversion. This patient’s case, however, reminds us to remain alert to an uncommon pathologic cause of T-wave inversion. A 50-year-old African American male was brought to the emergency department by ambulance after his bizarre behavior caused a public disturbance. The patient denied recent chest discomfort and was without complaint upon arrival. He had a history of bipolar disorder and hypertension but had not been taking any of his prescribed medications. Further, he had no knowledge of his family’s medical history. In the emergency department, he was oriented only to self, and his blood pressure was elevated at 148/91 mm Hg. The examination, including neurologic assessment, was otherwise unremarkable. An ECG and laboratory tests were obtained with a plan to transfer the patient to a local psychiatric hospital for further management if the tests were normal.
ASSESSMENT The patient’s ECG revealed normal sinus rhythm, a heart rate of 74 beats per minute, a prolonged corrected QT interval, left ventricular hypertrophy (per the Cornell criteria), and giant T wave inversions in the inferior, lateral, and anterior leads (Figure 1). Despite the absence of neurological findings, the patient’s history, preadmission behavior, and Funding: None. Conflict of Interest: None. Authorship: All authors had access to the data and a role in writing this manuscript. The corresponding author is Ezra A. Amsterdam, MD, 4860 Y Street, Suite 2820, Sacramento, CA 95817. E-mail address: [email protected] 0002-9343/$ -see front matter Ó 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.amjmed.2014.02.028
ECG all raised concern for an acute cerebrovascular event, but computed tomography of the head showed no evidence of an intracranial process. His serum troponin I level was 0.04 ng/mL (reference, < 0.04 ng/mL). A cardiology consultation confirmed the normal cardiovascular examination, including the absence of abnormal apical impulse, murmur, or gallop. Left ventricular wall motion and the ejection fraction (65%) proved normal on a transthoracic echocardiogram. Marked left ventricular hypertrophy (thickness, 22 mm), predominantly at the apex, was noted (Figure 2). No intraventricular gradient existed in the left ventricle, and the remainder of the study was normal.
DIAGNOSIS The ECG and echocardiogram findings led to a diagnosis of apical hypertrophic cardiomyopathy. This uncommon morphologic variant of hypertrophic cardiomyopathy may be associated with sarcomere gene mutations; most commonly, MYBPC3 and MYH7. In contrast to the nonapical counterpart, however, only 13% of cases are genotype positive.2 While some studies have reported rates as high as 41% among Asians with hypertrophic cardiomyopathy, apical hypertrophic cardiomyopathy accounts for only about 1-3% of hypertrophic cardiomyopathy cases in the United States.3 Because the apical region of the left ventricle is predominantly involved, it is rarely associated with left ventricular outflow obstruction. For this reason, patients are frequently asymptomatic and do not routinely seek medical attention. Such was the case with our patient, in whom this diagnosis was an incidental finding. Of those who do present with symptoms, the most common complaints are related to diastolic dysfunction. Physical examination may reveal a forceful or sustained apical impulse with an S4 gallop. While a systolic ejection murmur that increases with the Valsalva maneuver is typically associated with hypertrophic obstructive cardiomyopathy, the same is uncommon in the apical type. ECG findings indicative of left ventricular hypertrophy with giant T-wave inversions (depth 10 mm), especially in the precordial leads, should raise suspicion for apical
Malik et al
Apical Hypertrophic Cardiomyopathy
499
Figure 1 The patient’s electrocardiogram showed normal sinus rhythm, a heart rate of 74 beats per minute, a prolonged corrected QT interval (513 ms), left ventricular hypertrophy (per the Cornell criteria), and extensive giant T-wave inversions in the inferior, lateral, and anterior leads.
hypertrophic cardiomyopathy.4 Although the cause of this phenomenon has yet to be described, giant T-wave inversions in the setting of left ventricular hypertrophy are considered by some to be pathognomonic of apical hypertrophic cardiomyopathy. However, because this condition is uncommon, it is important to be cognizant of other more frequent causes of this ECG finding, including myocardial ischemia, neurological disease, and even a benign form known as idiopathic global T-wave inversion syndrome.5 Echocardiography should be the initial imaging modality for patients with suspected apical hypertrophic cardiomyopathy. A left ventricular apical wall thickness of > 15 mm or a ratio of apical to basal left ventricular wall thickness of
Figure 2 A transthoracic echocardiogram (apical 2-chamber view) demonstrated marked left ventricular wall thickness (22 mm), predominantly at the apex. LV ¼ left ventricle; RV ¼ right ventricle; LA ¼ left atrium.
1.3-1.5 confirms the diagnosis.6 Magnetic resonance imaging (MRI) is valuable, affording quantification of cardiac chamber volumes, function, and mass. It also may depict a characteristic spade-like configuration of the left ventricular cavity during systole in patients with apical hypertrophic cardiomyopathy. In addition, MRI can identify extent and location of left ventricular fibrosis, which might be related to an adverse prognosis.7
MANAGEMENT Although initially thought to be a benign condition, recent data have shown an increased risk for sudden cardiac arrest, fatal arrhythmias, heart failure, and ischemic events in patients with apical hypertrophic cardiomyopathy. In a series of 105 patients with the condition, estimated survival was 95% at 15 years. However, 30% of these patients experienced a serious cardiac complication, most commonly atrial fibrillation (12%) or myocardial infarction (10%).8 Another study of 193 patients with apical hypertrophic cardiomyopathy showed a significantly increased risk for atrial fibrillation, pulmonary hypertension, and death in women as compared with men and an overall all-cause mortality rate of 29% during a median follow-up time of 78 months.9 Additionally, in a study of 454 patients with apical hypertrophic cardiomyopathy, the all-cause mortality rate was 9% during a median follow-up time of 43 months, with 25% of patients experiencing a major cardiac event during this time period.10 Treatment for this disorder is guided by clinical status. Calcium antagonists are the preferred therapy in patients who have apical hypertrophic cardiomyopathy with normal systolic function and impaired relaxation. Treatment of atrial arrhythmias is similar to that in other cardiac diseases and consists of pharmacotherapy, including anticoagulation,
500 and/or electrical cardioversion. Patients with apical hypertrophic cardiomyopathy also are at an increased risk for sudden cardiac death and should undergo risk stratification for prophylactic implantation of an implantable cardioverterdefibrillator. Our patient was transferred to an inpatient psychiatric unit and will receive further evaluation following discharge.
References 1. Fisch C. T wave abnormalities due to extracardiac “functional” causes. ACC Curr J Rev. 1997;6:101-104. 2. Gruner C, Care M, Siminovitch K, et al. Sarcomere protein gene mutations in patients with apical hypertrophic cardiomyopathy. Circ Cardiovasc Genet. 2011;4:288-295. 3. Yamaguchi H, Nishiyama S, Nakanishi S, Nishimura S. Electrocardiographic, echocardiographic, and ventriculographic characterization of hypertrophic non-obstructive cardiomyopathy. Eur Heart J. 1983;4(suppl F):105-119.
The American Journal of Medicine, Vol 127, No 6, June 2014 4. Sakamoto T, Tei C, Murayama M, Ichiyasu H, Hada Y. Giant T wave inversion as a manifestation of asymmetrical apical hypertrophy of the left ventricle. Echocardiographic and ultrasono-cardiotomographic study. Jpn Heart J. 1976;17:611-629. 5. Pillarisetti J, Gupta K. Giant inverted T waves in the emergency department: case report and review of differential diagnoses. J Electrocardiol. 2010;43:40-42. 6. Williams LK, Frenneaux MP, Steeds RP. Echocardiography in hypertrophic cardiomyopathy diagnosis, prognosis, and role in management. Eur J Echocardiogr. 2009;10:iii9-14. 7. To AC, Dhillon A, Desai MY. Cardiac magnetic resonance in hypertrophic cardiomyopathy. JACC Cardiovasc Imaging. 2011;4:1123-1137. 8. Eriksson MJ, Sonnenberg B, Woo A, et al. Long-term outcome in patients with apical hypertrophic cardiomyopathy. J Am Coll Cardiol. 2002;39:638-645. 9. Klarich KW, Attenhofer Jost CH, Binder J, et al. Risk of death in longterm follow-up of patients with apical hypertrophic cardiomyopathy. Am J Cardiol. 2013;111:1784-1791. 10. Moon J, Shim CY, Ha JW, et al. Clinical and echocardiographic predictors of outcomes in patients with apical hypertrophic cardiomyopathy. Am J Cardiol. 2011;108:1614-1619.
T-wave Tease: Apical Hypertrophic Cardiomyopathy Lindsey H. Malik, DO, Gagan D. Singh, MD, Ezra A. Amsterdam, MD Division of Cardiovascular Medicine, Department of Internal Medicine, University of California Davis Medical Center, Sacramento.
PRESENTATION The T wave of the electrocardiogram (ECG) represents ventricular repolarization and is typically concordant with the vector of the QRS complex. Its direction and morphology are influenced by numerous physiologic and pathophysiologic factors.1 Myocardial ischemia is among the most common and important diagnoses that should be considered upon recognition of T-wave inversion. This patient’s case, however, reminds us to remain alert to an uncommon pathologic cause of T-wave inversion. A 50-year-old African American male was brought to the emergency department by ambulance after his bizarre behavior caused a public disturbance. The patient denied recent chest discomfort and was without complaint upon arrival. He had a history of bipolar disorder and hypertension but had not been taking any of his prescribed medications. Further, he had no knowledge of his family’s medical history. In the emergency department, he was oriented only to self, and his blood pressure was elevated at 148/91 mm Hg. The examination, including neurologic assessment, was otherwise unremarkable. An ECG and laboratory tests were obtained with a plan to transfer the patient to a local psychiatric hospital for further management if the tests were normal.
ASSESSMENT The patient’s ECG revealed normal sinus rhythm, a heart rate of 74 beats per minute, a prolonged corrected QT interval, left ventricular hypertrophy (per the Cornell criteria), and giant T wave inversions in the inferior, lateral, and anterior leads (Figure 1). Despite the absence of neurological findings, the patient’s history, preadmission behavior, and Funding: None. Conflict of Interest: None. Authorship: All authors had access to the data and a role in writing this manuscript. The corresponding author is Ezra A. Amsterdam, MD, 4860 Y Street, Suite 2820, Sacramento, CA 95817. E-mail address: [email protected] 0002-9343/$ -see front matter Ó 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.amjmed.2014.02.028
ECG all raised concern for an acute cerebrovascular event, but computed tomography of the head showed no evidence of an intracranial process. His serum troponin I level was 0.04 ng/mL (reference, < 0.04 ng/mL). A cardiology consultation confirmed the normal cardiovascular examination, including the absence of abnormal apical impulse, murmur, or gallop. Left ventricular wall motion and the ejection fraction (65%) proved normal on a transthoracic echocardiogram. Marked left ventricular hypertrophy (thickness, 22 mm), predominantly at the apex, was noted (Figure 2). No intraventricular gradient existed in the left ventricle, and the remainder of the study was normal.
DIAGNOSIS The ECG and echocardiogram findings led to a diagnosis of apical hypertrophic cardiomyopathy. This uncommon morphologic variant of hypertrophic cardiomyopathy may be associated with sarcomere gene mutations; most commonly, MYBPC3 and MYH7. In contrast to the nonapical counterpart, however, only 13% of cases are genotype positive.2 While some studies have reported rates as high as 41% among Asians with hypertrophic cardiomyopathy, apical hypertrophic cardiomyopathy accounts for only about 1-3% of hypertrophic cardiomyopathy cases in the United States.3 Because the apical region of the left ventricle is predominantly involved, it is rarely associated with left ventricular outflow obstruction. For this reason, patients are frequently asymptomatic and do not routinely seek medical attention. Such was the case with our patient, in whom this diagnosis was an incidental finding. Of those who do present with symptoms, the most common complaints are related to diastolic dysfunction. Physical examination may reveal a forceful or sustained apical impulse with an S4 gallop. While a systolic ejection murmur that increases with the Valsalva maneuver is typically associated with hypertrophic obstructive cardiomyopathy, the same is uncommon in the apical type. ECG findings indicative of left ventricular hypertrophy with giant T-wave inversions (depth 10 mm), especially in the precordial leads, should raise suspicion for apical
Malik et al
Apical Hypertrophic Cardiomyopathy
499
Figure 1 The patient’s electrocardiogram showed normal sinus rhythm, a heart rate of 74 beats per minute, a prolonged corrected QT interval (513 ms), left ventricular hypertrophy (per the Cornell criteria), and extensive giant T-wave inversions in the inferior, lateral, and anterior leads.
hypertrophic cardiomyopathy.4 Although the cause of this phenomenon has yet to be described, giant T-wave inversions in the setting of left ventricular hypertrophy are considered by some to be pathognomonic of apical hypertrophic cardiomyopathy. However, because this condition is uncommon, it is important to be cognizant of other more frequent causes of this ECG finding, including myocardial ischemia, neurological disease, and even a benign form known as idiopathic global T-wave inversion syndrome.5 Echocardiography should be the initial imaging modality for patients with suspected apical hypertrophic cardiomyopathy. A left ventricular apical wall thickness of > 15 mm or a ratio of apical to basal left ventricular wall thickness of
Figure 2 A transthoracic echocardiogram (apical 2-chamber view) demonstrated marked left ventricular wall thickness (22 mm), predominantly at the apex. LV ¼ left ventricle; RV ¼ right ventricle; LA ¼ left atrium.
1.3-1.5 confirms the diagnosis.6 Magnetic resonance imaging (MRI) is valuable, affording quantification of cardiac chamber volumes, function, and mass. It also may depict a characteristic spade-like configuration of the left ventricular cavity during systole in patients with apical hypertrophic cardiomyopathy. In addition, MRI can identify extent and location of left ventricular fibrosis, which might be related to an adverse prognosis.7
MANAGEMENT Although initially thought to be a benign condition, recent data have shown an increased risk for sudden cardiac arrest, fatal arrhythmias, heart failure, and ischemic events in patients with apical hypertrophic cardiomyopathy. In a series of 105 patients with the condition, estimated survival was 95% at 15 years. However, 30% of these patients experienced a serious cardiac complication, most commonly atrial fibrillation (12%) or myocardial infarction (10%).8 Another study of 193 patients with apical hypertrophic cardiomyopathy showed a significantly increased risk for atrial fibrillation, pulmonary hypertension, and death in women as compared with men and an overall all-cause mortality rate of 29% during a median follow-up time of 78 months.9 Additionally, in a study of 454 patients with apical hypertrophic cardiomyopathy, the all-cause mortality rate was 9% during a median follow-up time of 43 months, with 25% of patients experiencing a major cardiac event during this time period.10 Treatment for this disorder is guided by clinical status. Calcium antagonists are the preferred therapy in patients who have apical hypertrophic cardiomyopathy with normal systolic function and impaired relaxation. Treatment of atrial arrhythmias is similar to that in other cardiac diseases and consists of pharmacotherapy, including anticoagulation,
500 and/or electrical cardioversion. Patients with apical hypertrophic cardiomyopathy also are at an increased risk for sudden cardiac death and should undergo risk stratification for prophylactic implantation of an implantable cardioverterdefibrillator. Our patient was transferred to an inpatient psychiatric unit and will receive further evaluation following discharge.
References 1. Fisch C. T wave abnormalities due to extracardiac “functional” causes. ACC Curr J Rev. 1997;6:101-104. 2. Gruner C, Care M, Siminovitch K, et al. Sarcomere protein gene mutations in patients with apical hypertrophic cardiomyopathy. Circ Cardiovasc Genet. 2011;4:288-295. 3. Yamaguchi H, Nishiyama S, Nakanishi S, Nishimura S. Electrocardiographic, echocardiographic, and ventriculographic characterization of hypertrophic non-obstructive cardiomyopathy. Eur Heart J. 1983;4(suppl F):105-119.
The American Journal of Medicine, Vol 127, No 6, June 2014 4. Sakamoto T, Tei C, Murayama M, Ichiyasu H, Hada Y. Giant T wave inversion as a manifestation of asymmetrical apical hypertrophy of the left ventricle. Echocardiographic and ultrasono-cardiotomographic study. Jpn Heart J. 1976;17:611-629. 5. Pillarisetti J, Gupta K. Giant inverted T waves in the emergency department: case report and review of differential diagnoses. J Electrocardiol. 2010;43:40-42. 6. Williams LK, Frenneaux MP, Steeds RP. Echocardiography in hypertrophic cardiomyopathy diagnosis, prognosis, and role in management. Eur J Echocardiogr. 2009;10:iii9-14. 7. To AC, Dhillon A, Desai MY. Cardiac magnetic resonance in hypertrophic cardiomyopathy. JACC Cardiovasc Imaging. 2011;4:1123-1137. 8. Eriksson MJ, Sonnenberg B, Woo A, et al. Long-term outcome in patients with apical hypertrophic cardiomyopathy. J Am Coll Cardiol. 2002;39:638-645. 9. Klarich KW, Attenhofer Jost CH, Binder J, et al. Risk of death in longterm follow-up of patients with apical hypertrophic cardiomyopathy. Am J Cardiol. 2013;111:1784-1791. 10. Moon J, Shim CY, Ha JW, et al. Clinical and echocardiographic predictors of outcomes in patients with apical hypertrophic cardiomyopathy. Am J Cardiol. 2011;108:1614-1619.
