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Apical hypertrophic cardiomyopathy: Bedside diagnosis by intravenous contrast echocardiography
Apical Hypertrophic Cardiomyopathy: Bedside Diagnosis by Intravenous Contrast Echocardiography Prem Soman, MD, MRCP, John Swinburn, MRCP, Mathew Callister, MRCP, Nigel G. Stephens, PhD, FRCP, and Roxy Senior, MD, DM, FRCP, Harrow, United Kingdom
Apical cardiomyopathy is rare in the West. The characteristic appearance on left ventriculography has been used to confirm the diagnosis of this condition; transthoracic echocardiography can also be useful in this regard. However, apical artifacts may obscure the typical appearance during echocardiography, and although the advent of tissue harmonic echocardiography has resulted in improved image quality, the technique still may be inadequate in the establishment of a diagnosis. We hypothesized that contrast echocardiography, which improves endocardial border delineation, may be the
technique of choice for the diagnosis of apical hypertrophic cardiomyopathy. We report the case of a 40-year-old woman with Down syndrome who had chest pain. The electrocardiogram showed T-wave changes in the lateral precordial leads, but cardiac enzymes were normal. Tissue harmonic echocardiography showed apical akinesia. Intravenous contrast echocardiography, however, revealed typical features of hypertrophic apical cardiomyopathy. Thus contrast echocardiography may be used to establish the diagnosis of this condition. (J Am Soc Echocardiogr 2001;14:311-3.)
Apical hypertrophic cardiomyopathy, characterized
CASE REPORT
by left ventricular hypertrophy localized to the apex, is rare except in Japan where it represents almost a quarter of all cases of hypertrophic cardiomyopathy (HCM).1 It is also typified by the presence of giant inverted T waves in the precordial leads on electrocardiography, the absence of an intraventricular gradient, and a generally benign course.2,3 The diagnosis is traditionally confirmed by left ventricular angiography, which demonstrates a spade-like appearance of the left ventricular cavity caused by near obliteration of the apex by the hypertrophy.4 We report a case of apical HCM in which the diagnosis was confirmed noninvasively at the bedside with the use of intravenous contrast echocardiography.
A 40-year-old woman with Down syndrome was admitted with chest pain suggestive of angina pectoris. There was no history of syncope, palpitation, or shortness of breath. Examination revealed normal peripheral pulses, blood pressure, and jugular venous pressure as well as a heaving apical impulse and a fourth heart sound. Chest x-ray results were normal. The electrocardiogram showed inverted T waves in the lateral precordial leads (Figure 1).There was no elevation in cardiac enzymes. A differential diagnosis of unstable angina or apical HCM was made.Two-dimensional echocardiography was performed in the tissue harmonic mode with a 3-2–MHz transducer (HDI 5000 CV, Advance Technology Laboratories,Bothell,Wash).The apex appeared akinetic, whereas the rest of the left ventricle was contracting normally (Figure 2).Because the clinical differential diagnoses included apical HCM, contrast echocardiography was performed with an intravenous injection of 0.5 mL of contrast agent (Optison). The classical spade-like appearance of the left ventricular cavity was seen and confirmed the diagnosis of apical HCM (Figure 3).
From the Department of Cardiovascular Medicine, Northwick Park Hospital, and the Institute of Medical Research, Harrow, United Kingdom. Reprint requests: Roxy Senior, MD, DM, FRCP (Lond), Department of Cardiology, Northwick Park Hospital, Watford Road, Harrow, Middlesex HA1 3UJ, UK. Copyright © 2001 by the American Society of Echocardiography. 0894-7317/2001/$35.00 + 0 27/4/108475 doi:10.1067/mje.2001.108475
DISCUSSION The diagnosis of apical HCM depends on the demonstration of the classical distribution of left ventricular
311
Journal of the American Society of Echocardiography April 2001
312 Soman et al
Figure 1 Electrocardiogram showing inverted T waves in the lateral precordial leads.
Figure 2 Two-dimensional echocardiography. The apex (arrows) appears akinetic, whereas the rest of the left ventricle (LV) contracts normally.
hypertrophy and has traditionally been made on left ventricular angiography. This is, however, an invasive procedure and involves a radiation dose to the patient.Two-dimensional echocardiography may also be used to make the diagnosis. However, visualization of the apical region may be obscured by reverberation artifacts from the chest wall and ribs. The use of second harmonic imaging significantly enhances endocardial visualization,5,6 but apical definition may still remain inadequate, especially in patients with a thin chest wall. This is because the ultrasound wave has to travel some distance in the tissue before harmonic frequencies are generated.7
Hence apical hypertrophy could be misinterpreted as akinesia, as was seen in this patient. The accurate assessment of regional wall thickening in patients with HCM is particularly relevant because as many as 75% of these patients present with angina.4 Angina may be caused by a variety of mechanisms, including imbalance between oxygen supply and demand resulting from the ventricular hypertrophy; microvascular disease; diastolic dysfunction; and epicardial atheromatous obstructive coronary artery disease. Transmural myocardial infarction may occur in the absence of epicardial coronary disease.4 Contrast echocardiography can be performed quick-
Journal of the American Society of Echocardiography Volume 14 Number 4
Soman et al 313
Figure 3 Two-dimensional echocardiography with an intravenous injection of 0.5 mL of contrast agent (Optison). The classical spade-like appearance of the left ventricular cavity is seen (arrows), confirming the diagnosis of apical hypertrophic cardiomyopathy. LV, Left ventricle.
ly and noninvasively at the bedside.The demonstration of a spade-like appearance of the left ventricular cavity is analogous to the similar finding on left ventricular angiography and is diagnostic of apical HCM. In this patient, the appearances were convincing enough to obviate the need for any further investigation. Contrast echocardiography is currently licensed for the enhancement of left ventricular cavity definition in subjects with a difficult echocardiographic window.8 It has potential utility for the enhanced delineation of regional left ventricular dysfunction, thrombi, and masses at the apex. To our knowledge, this is the first reported use of this technique for the diagnosis of apical HCM. REFERENCES 1. Maron BJ. Apical hypertrophic cardiomyopathy: the continuing saga. J Am Coll Cardiol 1990;15:91-3.
2. Louie EK, Maron BJ. Apical Hypertrophic cardiomyopathy: clinical and two-dimensional echocardiographic assessment. Ann Intern Med 1987;106:663-7. 3. Webb JG, Sasson Z, Rakowski H, et al. Apical hypertrophic cardiomyopathy: clinical follow-up and diagnostic correlates. J Am Coll Cardiol 1990;15:83-9. 4. Wynne J and Braunwald E. The cardiomyopathies and myocarditides. In: Braunwald E, editor. Heart disease: a textbook of cardiovascular medicine. 5th ed. Philadelphia: WB Saunders Company; 1997. p. 1404-64. 5. Senior R, Soman P, Khattar RS, Lahiri A. Improved endocardial visualisation using second harmonic compared to fundamental two-dimensional echocardiographic imaging. Am Heart J 1999;138:163-8. 6. Spencer KT, Bednarz J, Rafter PG, et al. Use of harmonic imaging without echocardiographic contrast to improve two dimensional image quality. Am J Cardiol 1998;82:7949. 7. Thomas JD, Rubin DN. Tissue harmonic imaging: why does it work? J Am Soc Echocardiogr 1998;11:803-8. 8. Senior R. Role of contrast echo for the assessment of LV function. Echocardiography 1999;7:747-53.
Apical cardiomyopathy is rare in the West. The characteristic appearance on left ventriculography has been used to confirm the diagnosis of this condition; transthoracic echocardiography can also be useful in this regard. However, apical artifacts may obscure the typical appearance during echocardiography, and although the advent of tissue harmonic echocardiography has resulted in improved image quality, the technique still may be inadequate in the establishment of a diagnosis. We hypothesized that contrast echocardiography, which improves endocardial border delineation, may be the
technique of choice for the diagnosis of apical hypertrophic cardiomyopathy. We report the case of a 40-year-old woman with Down syndrome who had chest pain. The electrocardiogram showed T-wave changes in the lateral precordial leads, but cardiac enzymes were normal. Tissue harmonic echocardiography showed apical akinesia. Intravenous contrast echocardiography, however, revealed typical features of hypertrophic apical cardiomyopathy. Thus contrast echocardiography may be used to establish the diagnosis of this condition. (J Am Soc Echocardiogr 2001;14:311-3.)
Apical hypertrophic cardiomyopathy, characterized
CASE REPORT
by left ventricular hypertrophy localized to the apex, is rare except in Japan where it represents almost a quarter of all cases of hypertrophic cardiomyopathy (HCM).1 It is also typified by the presence of giant inverted T waves in the precordial leads on electrocardiography, the absence of an intraventricular gradient, and a generally benign course.2,3 The diagnosis is traditionally confirmed by left ventricular angiography, which demonstrates a spade-like appearance of the left ventricular cavity caused by near obliteration of the apex by the hypertrophy.4 We report a case of apical HCM in which the diagnosis was confirmed noninvasively at the bedside with the use of intravenous contrast echocardiography.
A 40-year-old woman with Down syndrome was admitted with chest pain suggestive of angina pectoris. There was no history of syncope, palpitation, or shortness of breath. Examination revealed normal peripheral pulses, blood pressure, and jugular venous pressure as well as a heaving apical impulse and a fourth heart sound. Chest x-ray results were normal. The electrocardiogram showed inverted T waves in the lateral precordial leads (Figure 1).There was no elevation in cardiac enzymes. A differential diagnosis of unstable angina or apical HCM was made.Two-dimensional echocardiography was performed in the tissue harmonic mode with a 3-2–MHz transducer (HDI 5000 CV, Advance Technology Laboratories,Bothell,Wash).The apex appeared akinetic, whereas the rest of the left ventricle was contracting normally (Figure 2).Because the clinical differential diagnoses included apical HCM, contrast echocardiography was performed with an intravenous injection of 0.5 mL of contrast agent (Optison). The classical spade-like appearance of the left ventricular cavity was seen and confirmed the diagnosis of apical HCM (Figure 3).
From the Department of Cardiovascular Medicine, Northwick Park Hospital, and the Institute of Medical Research, Harrow, United Kingdom. Reprint requests: Roxy Senior, MD, DM, FRCP (Lond), Department of Cardiology, Northwick Park Hospital, Watford Road, Harrow, Middlesex HA1 3UJ, UK. Copyright © 2001 by the American Society of Echocardiography. 0894-7317/2001/$35.00 + 0 27/4/108475 doi:10.1067/mje.2001.108475
DISCUSSION The diagnosis of apical HCM depends on the demonstration of the classical distribution of left ventricular
311
Journal of the American Society of Echocardiography April 2001
312 Soman et al
Figure 1 Electrocardiogram showing inverted T waves in the lateral precordial leads.
Figure 2 Two-dimensional echocardiography. The apex (arrows) appears akinetic, whereas the rest of the left ventricle (LV) contracts normally.
hypertrophy and has traditionally been made on left ventricular angiography. This is, however, an invasive procedure and involves a radiation dose to the patient.Two-dimensional echocardiography may also be used to make the diagnosis. However, visualization of the apical region may be obscured by reverberation artifacts from the chest wall and ribs. The use of second harmonic imaging significantly enhances endocardial visualization,5,6 but apical definition may still remain inadequate, especially in patients with a thin chest wall. This is because the ultrasound wave has to travel some distance in the tissue before harmonic frequencies are generated.7
Hence apical hypertrophy could be misinterpreted as akinesia, as was seen in this patient. The accurate assessment of regional wall thickening in patients with HCM is particularly relevant because as many as 75% of these patients present with angina.4 Angina may be caused by a variety of mechanisms, including imbalance between oxygen supply and demand resulting from the ventricular hypertrophy; microvascular disease; diastolic dysfunction; and epicardial atheromatous obstructive coronary artery disease. Transmural myocardial infarction may occur in the absence of epicardial coronary disease.4 Contrast echocardiography can be performed quick-
Journal of the American Society of Echocardiography Volume 14 Number 4
Soman et al 313
Figure 3 Two-dimensional echocardiography with an intravenous injection of 0.5 mL of contrast agent (Optison). The classical spade-like appearance of the left ventricular cavity is seen (arrows), confirming the diagnosis of apical hypertrophic cardiomyopathy. LV, Left ventricle.
ly and noninvasively at the bedside.The demonstration of a spade-like appearance of the left ventricular cavity is analogous to the similar finding on left ventricular angiography and is diagnostic of apical HCM. In this patient, the appearances were convincing enough to obviate the need for any further investigation. Contrast echocardiography is currently licensed for the enhancement of left ventricular cavity definition in subjects with a difficult echocardiographic window.8 It has potential utility for the enhanced delineation of regional left ventricular dysfunction, thrombi, and masses at the apex. To our knowledge, this is the first reported use of this technique for the diagnosis of apical HCM. REFERENCES 1. Maron BJ. Apical hypertrophic cardiomyopathy: the continuing saga. J Am Coll Cardiol 1990;15:91-3.
2. Louie EK, Maron BJ. Apical Hypertrophic cardiomyopathy: clinical and two-dimensional echocardiographic assessment. Ann Intern Med 1987;106:663-7. 3. Webb JG, Sasson Z, Rakowski H, et al. Apical hypertrophic cardiomyopathy: clinical follow-up and diagnostic correlates. J Am Coll Cardiol 1990;15:83-9. 4. Wynne J and Braunwald E. The cardiomyopathies and myocarditides. In: Braunwald E, editor. Heart disease: a textbook of cardiovascular medicine. 5th ed. Philadelphia: WB Saunders Company; 1997. p. 1404-64. 5. Senior R, Soman P, Khattar RS, Lahiri A. Improved endocardial visualisation using second harmonic compared to fundamental two-dimensional echocardiographic imaging. Am Heart J 1999;138:163-8. 6. Spencer KT, Bednarz J, Rafter PG, et al. Use of harmonic imaging without echocardiographic contrast to improve two dimensional image quality. Am J Cardiol 1998;82:7949. 7. Thomas JD, Rubin DN. Tissue harmonic imaging: why does it work? J Am Soc Echocardiogr 1998;11:803-8. 8. Senior R. Role of contrast echo for the assessment of LV function. Echocardiography 1999;7:747-53.