- Email: [email protected]
Transvenous biopsy of intracardiac tumor under transesophageal echocardiographic guidance
aJune
1782
Salka, Siegel, and Sagar
American
Spink WW. Some biologic and clinical tracellular parasitism in brucellosis.
problems N Engl
related J Med
to inJ9Fj2:
1993
Heart Journal
Reprint requests: Kiran B. Sagar, MD, Division of Cardiology, Eox 123. Milwaukee County Medical Complex, 8700 W. Wisconsin Ave., Milwaukee. WI 53226.
aly, ascites, bilat.eral leg edema, and flapping tremors. N(J jugular vein distention was noted. The patient was rehydrated with normalization of his mental status. An ultrasound examination of t,he abdomen revealed no biliary ductal dilatation or hepatic renal or splenic masses. Because of the suspicion of Budd-Chiari syndrome, angiography of the iliac vein and inferior vena cava was performed, which revealed complete occlusion of the vena cava at the iliac junction with opacification of numerous paraspinous and lumbar collateral vessels but not of the inferior vena cava or hepatic vein. Subsequently a right atria1 angiogram from the brachial approach revealed no evidence of any patency of the hepatic vein or the inferior vena cava more than 1 inch below the point of right atria1 insertion. The patient was started on a regimen of heparin and referred to our hospital for further evaluation and possible thrombolytic therapy. At our hospual two-dimensional TTE was carried out. A 2 to ~3cm nonmobile right atria1 mass was seen only in the apical four-chamber view. The study was technically difficult; therefore it was thought that TEE was necessary to further delineate the nature of the right atria1 mass. A major concern at that time was whether the mass was indeed a tIllnor, in which case thrombolytic therapy would be contraindicated. or whether it represented a thrombus. in which case thrombolytic therapy would be a consideration. Therefore it -was recommended that the mass be biopsietl transvenously with the use of TEE for guidance of the biopsy forceps. In the catheterization laboratory an 8E’ sheath was inserted into the right internal jugular vein without difhculty; a modified Seldinger technique was used and I( ( local xylocaine anesthetic was administered. TEE was performed without complications after the patient received 3 mg of Versed and 37.5 mg of Demerol intravenously. A 5 MHz single-plane transducer was used. A 2 x 2 cm right atria1 mass was clearly visible. It was attached to the right atria1 wall and extended to the inferior vena cava (Fig. 1). At this point a Mansfield 1.8 mm biopsy forceps was inserted and was easily visualized with transesophageal imaging (Fig. 2). The biopsy forceps was positioned on the mass, and eight. samples were obtained. There were no complications during the procedure. Microscopic examinat,ion of the biopsy specimens revealed fragments of myocardium and segments of endothelium with infiltrating tumor. The tumor mass was believed to represent metastatic adenocarcinoma of an unknown primary origin. An immunoperoxidase stain for prostate specific antigen was negative. Evaluation before and after the biopsy procedure by means of computed tomographic scanning with contrast of the thorax and abdomen imaging and esophagogastroduodenoscopy provided no information as to the origin of the metastatic tumor. The patient’s condition worsened and he died of encephalopathy. Permission for autopsy was denied. Intracardiac masses noted on echocardiography frequently present a diagnostic challenge to the clinician.l*‘l, .’
A,M HEAKI‘ ,J 1993;125:1782-1784
They
Copyright ’ 1993 by Mosby-Year Book, 0002-8703/93/$1,00 + .I0 4/4/45670
generally fall into three categories: intramural thrombi, primary cardiac neoplasms, and tumors metastasizing to
:i.
247:6(X-10.
Delvecchio G, Fracassetti 0, Lorenzi N. Brucella endocarditis. Int J Cardiol 1991;33:328-9. c5 cJeroudi MO, Halim MA, Harder EJ, Al-Siba’i MB, Ziady G, Mercer EN. Brucella endocarditis. Br Heart
4.
Transvenous biopsy of intracardiac tumor under transesophageal echocardiographic guidance Samer Salka, MD, Ronald Siegel, MD, and Kiran B. Sagar, MD Milwaukee, Wis.
Endomyocardial biopsy has emerged as a very useful technique for detecting rejection after orthotrophic cardiac transplantation, diagnosing anthracylcine cytotoxicity in patients with cancer, identifying some forms of cardiomyopathy, and obtaining tissue diagnosis of intracardiac masses.l The technique usually uses fluoroscopic guidance to obtain biopsy samples. However, this limits the sites in the myocardium from which samples can be obtained (usually the right ventricular septum).:! Moreover, in the case of endocardial masses or procedures involving the left ventricle, biopsy guided by fluoroscopy alone may be hazardous, unfruitful, or both. Two-dimensional transthoracic echocardiography (TTE) has proved to be helpful in guiding the procedure of endomyocardial biopsy in patients after cardiac transplantation and in patients with intracardiac masses.2-4 Unfortunately TTE views may be limited in some patients and thus may fail to be of significant help in guiding endomyocardial biopsy. We present a case of metastatic carcinoma to the right atrium involving the inferior vena cava, which was diagnosed by transvenous biopsy of the tumor under the guidance of transesophageal echocardiography (TEE). The applicability of this technique for obtaining tissue samples for the diagnosis of intracardiac masses is discussed. The patient, a 62-year-old white man, was a nonsmoker with no history of alcohol abuse or any known medical problems, who was first seen at a local hospital with dehydration and hepatic encephalopathy. Physical examination findings included the following: an S4 gallop, hepatomeg-
From the Division of Wisconsin.
of Cardiology,
Department
Inc.
of Medicine,
Medical
College
represent
a wide
variety
of pathologic
conditions
but
Volume 125, Number 6 American Heart Journal
Salka, Siegel, and Sagar
Fig. 1. Transesophageal echocardiogram, adjacent to inferior vena cava. M, Tumor
Fig.
2. Bioptome
four-chamber mass.
view. Soft tissue mass (2.2 cm) in right
tip is seen on top of right
the heart. Although the diagnosis is often aided by the clinical history and the appearance of the mass on the echocardiogram, diagnostic uncertainty remains.a 7 Primary cardiac tumors are extremely rare, with an incidence ranging from 0.0017% to 0.28% in necropsy specimens. Fifty percent of these tumors are myxomas. Metastatic involvement of the heart in malignant tumors was thought to be rare but in fact has been reported to be present in 10 C;; to 20 % of patients dying of cancer.“, g The most common responsible tumors are those attributed to bronchogenic carcinoma, breast carcinoma, malignant melanoma, lymphoma, and leukemia. ‘-11 Right atria1 metastatic tumors are also associated with testicular, renal, and hepatic
atria1 tumor
mass. B, Bioptome
1783
atrium
tip.
tumorsll, l2 and can produce tumor thrombosis.11,12 Involvement from leukemia is mostly microscopic, but with lymphoma and visceral tumors gross lesions are identified in more than two thirds of involved autopsy specimens. Among those, endocardial involvement occurs in 20% to 27 % .l” In another study of 525 patients dying of visceral cancer, 61 had grossly visible cardiac metastases and more than one third of them had evidence of myocardial or epicardial involvement.” It is unclear how many of those patients with gross evidence of tumor pathologically in the endocardium or myocardium would have had intracardiac masses demonstrable by echocardiography. Two-dimensional TTE has long been used to diagnose
1784
Ahmed
June 1993 American Heart Journal
et al.
intracardiac masses, often incidentally. However, in some patients such as ours, characterization of the mass may be difficult because of technical limitations. TEE offers better resolution and therefore diagnostic accuracy particularly with left-sided cardiac involvement. In a recent report by Fegan et al.,‘” TEE was able to detect a recurrent right ventricular myxoma that was missed by TTE. TEE has been used to guide catheter positioning in procedures such asablation of accessarypathways in Wolf-Parkinson White syndrome. The endomyocardial biopsy procedure is a safe nonsurgical approach for obtaining biopsy samples from endocardial masses,where tissue confirmation is frequently needed before specific potentially harmful therapy in indicated (e.g., surgery, radiation therapy, chemotherapy, or thrombolysis/anticoagulation). The endomyocardial biopsy procedure is usually performed under fluoroscopic guidance.‘, 5 However, when the procedure is used under fluoroscopic guidance alone, only samples from the intraventricular septum can be obtained safely.’ Miller et al.” have recently reported the utility and safety of endomyocardial biopsy done under TTE guidance in patients after orthotropic
cardiac
transplantation.
The
biopt.ome
tip
10. 11. 12.
13.
dimensional echocardiography. In: Kapoor A, ed (‘ancer 01 the heart. Berlin: Springer-Verlag, 1986:X)-61 Bisel HF, Wroblewski F, LaDue +JS. Incidence and clinicai manifestations of cardiac metastases. *JAMA 1953;15:?712-5. Hanfling SM. Metastatic cancer to the heart, Circulation 1960;22:474-83. Goldman AP, Kotler MN, Parry WR. Atrial tumors. In: Kapoor A, ed. Cancer of the heart. Berlin: Springer-Verlag. 1986:81-109. Fagan LF, Caste110 R, Barner H, Moran M, Labovitz AJ. Transesophageal echocardiographic diagnosis of recurrent right ventricular myxoma 2 years after excision of right atrial myxoma. AM HEAFX J 1990;120:1456-8.
Dual antegrade His bundle pathways with alternating bundle branch block Rafique Ahmed, MD, PhD, Philip T. Sager, MD, Mahnaz Behboodikah, MD, and Bramah N. Singh, MD. PhD Los Angeles, Calif.
could always be seen, and biopsy specimens could be obtained from the cardiac apex and the right ventricular free wall in those patients. Other investigators33 ’ used TTE with fluoroscopy for guidance of transvenous biopsy of intracardiac atria1 tumors. Our case demonstrates the usefulness of TEE in obtaining tissue diagnosis in a patient with an intracardiac mass. Results of TTE were suboptimal, whereas TEE was helpful in guiding the bioptome during transvenous endomyocardial biopsy. This technique is safe and offers less radiation exposure and better image resolution, and it is more precise in positioning the bioptome. REFERENCES
1. Flipse TR, Tazelaar HD, Holmes Jr DR. Diagnosis of malignant cardiac disease by endomyocardial biopsy. Mayo Clin Proc 1990;65:1415-22. 2. Miller LW, Labovitz AJ, McBride LA, Pennington DG, Kanter K. Echocardiography-guided encomyocardial biopsy. A 5-year experience. Circulation 1988;78(suppl III):III-99-102. 3. Morrone A, Gaglione A, Bortone A, Ileceto, Caruso G, Calabrese P, Chiddo A. Diagnosi mediante biopsia endomicardica di microcitoma polmonare metastatizzato in atrio. Cardiologia 1988;33:419-21. 4. Copeland JG, Valdes-Cruz L, Sahn DJ. Endomyocardial biopsy with fluoroscopic and two-dimensional echocardiographic guidance: case report of a patient suspected of having muitiplecardiac tumors.-Clin Cardiol 1984;7:449-52. biopsy revisited [Editorial]. 5. Aretz HT. The endomyocardial Mayo Clin Proc 1990;65:1506-9. 6. Thomas AC, Mills PG, Giggs NM, Davies JM. Secondary carcinoma of left atrium simulating - mvxoma. Br Heart .I 1980; ” 44:541-4.
Roudaut R, Reynaud P, Koch M, Durandet P, Gosse, Dallocchio M. L’echocardiogrphie bidimensionnele dans le diagnostic des metastases intracardiaques. Arch Ma1 Coeur 1990; 83:1435-g. 8. Malaret GE, Aliaga P. Metastatic disease to the heart. Cancer 1968;22:457-66. 9. Kotler MN. Metastatic cardiac tumors: recognition of pericardial, myocardial and endocardial involvement by two7.
Longitudinal dissociation in the His bundle has been suggested based on experimental studies’ and the finding that distal His bundle pacing in some patients with an electrocardiographic pattern of apparent bundle branch block (BBB) normalizes the ECG. ‘93 We report a case in which a dual His bundle pathway was observed during electrophysiologic study with a left or right BBB pattern depending on which pathway conducted the impulse. A 68-year-old man with a history of hypertension, coronary artery disease, and coronary artery bypass surgery was referred for evaluation of sustained ventricular tachycardia. Physical examination findings were unremarkable, and routine blood chemistry determinations were within normal limits. ECG showed normal sinus rhythm, a normal PR interval, and a normal QRS axis with a nonspecific intraventricular conduction defect. The patient was not taking any cardioactive medication at the time of initial evaluation. Electrophysiologic study was performed with three quadripolar catheters introduced through the right femoral vein and placed in the high right atrium, right ventricular apex, and across the tricuspid
valve for His bundle
re-
cording. During sinus rhythm the AH interval was 70 msec and the HV interval was 70 msec. Atria1 extrastimulus at a basic drive cycle length (BCL) of 600 msec demonstrated a normal QRS pattern at HI-Hz of 410 msec with an Ha-V2 interval of 75 msec (Fig. 1, top panel). At HI-HZ of 400 msec From the Section of Cardiology, Department of Medicine, West Los Angeles Veterans Administration Medical Center and UCLA School of Medicine. Reprint requests: Rafique Ahmed, MD, PhD, Section of Cardiology, Wl llE, West Los Angeles VA Medical Center. Wilshire and Sawtele Blvd., Los Angeles, CA 90073. AM HEART J 1993;125:1784-1786
Copyright
‘, 1993 by Mosby-Year
0002.8703/93/51.00
+ .lO
4/4/45671
Hook.
Inc.
1782
Salka, Siegel, and Sagar
American
Spink WW. Some biologic and clinical tracellular parasitism in brucellosis.
problems N Engl
related J Med
to inJ9Fj2:
1993
Heart Journal
Reprint requests: Kiran B. Sagar, MD, Division of Cardiology, Eox 123. Milwaukee County Medical Complex, 8700 W. Wisconsin Ave., Milwaukee. WI 53226.
aly, ascites, bilat.eral leg edema, and flapping tremors. N(J jugular vein distention was noted. The patient was rehydrated with normalization of his mental status. An ultrasound examination of t,he abdomen revealed no biliary ductal dilatation or hepatic renal or splenic masses. Because of the suspicion of Budd-Chiari syndrome, angiography of the iliac vein and inferior vena cava was performed, which revealed complete occlusion of the vena cava at the iliac junction with opacification of numerous paraspinous and lumbar collateral vessels but not of the inferior vena cava or hepatic vein. Subsequently a right atria1 angiogram from the brachial approach revealed no evidence of any patency of the hepatic vein or the inferior vena cava more than 1 inch below the point of right atria1 insertion. The patient was started on a regimen of heparin and referred to our hospital for further evaluation and possible thrombolytic therapy. At our hospual two-dimensional TTE was carried out. A 2 to ~3cm nonmobile right atria1 mass was seen only in the apical four-chamber view. The study was technically difficult; therefore it was thought that TEE was necessary to further delineate the nature of the right atria1 mass. A major concern at that time was whether the mass was indeed a tIllnor, in which case thrombolytic therapy would be contraindicated. or whether it represented a thrombus. in which case thrombolytic therapy would be a consideration. Therefore it -was recommended that the mass be biopsietl transvenously with the use of TEE for guidance of the biopsy forceps. In the catheterization laboratory an 8E’ sheath was inserted into the right internal jugular vein without difhculty; a modified Seldinger technique was used and I( ( local xylocaine anesthetic was administered. TEE was performed without complications after the patient received 3 mg of Versed and 37.5 mg of Demerol intravenously. A 5 MHz single-plane transducer was used. A 2 x 2 cm right atria1 mass was clearly visible. It was attached to the right atria1 wall and extended to the inferior vena cava (Fig. 1). At this point a Mansfield 1.8 mm biopsy forceps was inserted and was easily visualized with transesophageal imaging (Fig. 2). The biopsy forceps was positioned on the mass, and eight. samples were obtained. There were no complications during the procedure. Microscopic examinat,ion of the biopsy specimens revealed fragments of myocardium and segments of endothelium with infiltrating tumor. The tumor mass was believed to represent metastatic adenocarcinoma of an unknown primary origin. An immunoperoxidase stain for prostate specific antigen was negative. Evaluation before and after the biopsy procedure by means of computed tomographic scanning with contrast of the thorax and abdomen imaging and esophagogastroduodenoscopy provided no information as to the origin of the metastatic tumor. The patient’s condition worsened and he died of encephalopathy. Permission for autopsy was denied. Intracardiac masses noted on echocardiography frequently present a diagnostic challenge to the clinician.l*‘l, .’
A,M HEAKI‘ ,J 1993;125:1782-1784
They
Copyright ’ 1993 by Mosby-Year Book, 0002-8703/93/$1,00 + .I0 4/4/45670
generally fall into three categories: intramural thrombi, primary cardiac neoplasms, and tumors metastasizing to
:i.
247:6(X-10.
Delvecchio G, Fracassetti 0, Lorenzi N. Brucella endocarditis. Int J Cardiol 1991;33:328-9. c5 cJeroudi MO, Halim MA, Harder EJ, Al-Siba’i MB, Ziady G, Mercer EN. Brucella endocarditis. Br Heart
4.
Transvenous biopsy of intracardiac tumor under transesophageal echocardiographic guidance Samer Salka, MD, Ronald Siegel, MD, and Kiran B. Sagar, MD Milwaukee, Wis.
Endomyocardial biopsy has emerged as a very useful technique for detecting rejection after orthotrophic cardiac transplantation, diagnosing anthracylcine cytotoxicity in patients with cancer, identifying some forms of cardiomyopathy, and obtaining tissue diagnosis of intracardiac masses.l The technique usually uses fluoroscopic guidance to obtain biopsy samples. However, this limits the sites in the myocardium from which samples can be obtained (usually the right ventricular septum).:! Moreover, in the case of endocardial masses or procedures involving the left ventricle, biopsy guided by fluoroscopy alone may be hazardous, unfruitful, or both. Two-dimensional transthoracic echocardiography (TTE) has proved to be helpful in guiding the procedure of endomyocardial biopsy in patients after cardiac transplantation and in patients with intracardiac masses.2-4 Unfortunately TTE views may be limited in some patients and thus may fail to be of significant help in guiding endomyocardial biopsy. We present a case of metastatic carcinoma to the right atrium involving the inferior vena cava, which was diagnosed by transvenous biopsy of the tumor under the guidance of transesophageal echocardiography (TEE). The applicability of this technique for obtaining tissue samples for the diagnosis of intracardiac masses is discussed. The patient, a 62-year-old white man, was a nonsmoker with no history of alcohol abuse or any known medical problems, who was first seen at a local hospital with dehydration and hepatic encephalopathy. Physical examination findings included the following: an S4 gallop, hepatomeg-
From the Division of Wisconsin.
of Cardiology,
Department
Inc.
of Medicine,
Medical
College
represent
a wide
variety
of pathologic
conditions
but
Volume 125, Number 6 American Heart Journal
Salka, Siegel, and Sagar
Fig. 1. Transesophageal echocardiogram, adjacent to inferior vena cava. M, Tumor
Fig.
2. Bioptome
four-chamber mass.
view. Soft tissue mass (2.2 cm) in right
tip is seen on top of right
the heart. Although the diagnosis is often aided by the clinical history and the appearance of the mass on the echocardiogram, diagnostic uncertainty remains.a 7 Primary cardiac tumors are extremely rare, with an incidence ranging from 0.0017% to 0.28% in necropsy specimens. Fifty percent of these tumors are myxomas. Metastatic involvement of the heart in malignant tumors was thought to be rare but in fact has been reported to be present in 10 C;; to 20 % of patients dying of cancer.“, g The most common responsible tumors are those attributed to bronchogenic carcinoma, breast carcinoma, malignant melanoma, lymphoma, and leukemia. ‘-11 Right atria1 metastatic tumors are also associated with testicular, renal, and hepatic
atria1 tumor
mass. B, Bioptome
1783
atrium
tip.
tumorsll, l2 and can produce tumor thrombosis.11,12 Involvement from leukemia is mostly microscopic, but with lymphoma and visceral tumors gross lesions are identified in more than two thirds of involved autopsy specimens. Among those, endocardial involvement occurs in 20% to 27 % .l” In another study of 525 patients dying of visceral cancer, 61 had grossly visible cardiac metastases and more than one third of them had evidence of myocardial or epicardial involvement.” It is unclear how many of those patients with gross evidence of tumor pathologically in the endocardium or myocardium would have had intracardiac masses demonstrable by echocardiography. Two-dimensional TTE has long been used to diagnose
1784
Ahmed
June 1993 American Heart Journal
et al.
intracardiac masses, often incidentally. However, in some patients such as ours, characterization of the mass may be difficult because of technical limitations. TEE offers better resolution and therefore diagnostic accuracy particularly with left-sided cardiac involvement. In a recent report by Fegan et al.,‘” TEE was able to detect a recurrent right ventricular myxoma that was missed by TTE. TEE has been used to guide catheter positioning in procedures such asablation of accessarypathways in Wolf-Parkinson White syndrome. The endomyocardial biopsy procedure is a safe nonsurgical approach for obtaining biopsy samples from endocardial masses,where tissue confirmation is frequently needed before specific potentially harmful therapy in indicated (e.g., surgery, radiation therapy, chemotherapy, or thrombolysis/anticoagulation). The endomyocardial biopsy procedure is usually performed under fluoroscopic guidance.‘, 5 However, when the procedure is used under fluoroscopic guidance alone, only samples from the intraventricular septum can be obtained safely.’ Miller et al.” have recently reported the utility and safety of endomyocardial biopsy done under TTE guidance in patients after orthotropic
cardiac
transplantation.
The
biopt.ome
tip
10. 11. 12.
13.
dimensional echocardiography. In: Kapoor A, ed (‘ancer 01 the heart. Berlin: Springer-Verlag, 1986:X)-61 Bisel HF, Wroblewski F, LaDue +JS. Incidence and clinicai manifestations of cardiac metastases. *JAMA 1953;15:?712-5. Hanfling SM. Metastatic cancer to the heart, Circulation 1960;22:474-83. Goldman AP, Kotler MN, Parry WR. Atrial tumors. In: Kapoor A, ed. Cancer of the heart. Berlin: Springer-Verlag. 1986:81-109. Fagan LF, Caste110 R, Barner H, Moran M, Labovitz AJ. Transesophageal echocardiographic diagnosis of recurrent right ventricular myxoma 2 years after excision of right atrial myxoma. AM HEAFX J 1990;120:1456-8.
Dual antegrade His bundle pathways with alternating bundle branch block Rafique Ahmed, MD, PhD, Philip T. Sager, MD, Mahnaz Behboodikah, MD, and Bramah N. Singh, MD. PhD Los Angeles, Calif.
could always be seen, and biopsy specimens could be obtained from the cardiac apex and the right ventricular free wall in those patients. Other investigators33 ’ used TTE with fluoroscopy for guidance of transvenous biopsy of intracardiac atria1 tumors. Our case demonstrates the usefulness of TEE in obtaining tissue diagnosis in a patient with an intracardiac mass. Results of TTE were suboptimal, whereas TEE was helpful in guiding the bioptome during transvenous endomyocardial biopsy. This technique is safe and offers less radiation exposure and better image resolution, and it is more precise in positioning the bioptome. REFERENCES
1. Flipse TR, Tazelaar HD, Holmes Jr DR. Diagnosis of malignant cardiac disease by endomyocardial biopsy. Mayo Clin Proc 1990;65:1415-22. 2. Miller LW, Labovitz AJ, McBride LA, Pennington DG, Kanter K. Echocardiography-guided encomyocardial biopsy. A 5-year experience. Circulation 1988;78(suppl III):III-99-102. 3. Morrone A, Gaglione A, Bortone A, Ileceto, Caruso G, Calabrese P, Chiddo A. Diagnosi mediante biopsia endomicardica di microcitoma polmonare metastatizzato in atrio. Cardiologia 1988;33:419-21. 4. Copeland JG, Valdes-Cruz L, Sahn DJ. Endomyocardial biopsy with fluoroscopic and two-dimensional echocardiographic guidance: case report of a patient suspected of having muitiplecardiac tumors.-Clin Cardiol 1984;7:449-52. biopsy revisited [Editorial]. 5. Aretz HT. The endomyocardial Mayo Clin Proc 1990;65:1506-9. 6. Thomas AC, Mills PG, Giggs NM, Davies JM. Secondary carcinoma of left atrium simulating - mvxoma. Br Heart .I 1980; ” 44:541-4.
Roudaut R, Reynaud P, Koch M, Durandet P, Gosse, Dallocchio M. L’echocardiogrphie bidimensionnele dans le diagnostic des metastases intracardiaques. Arch Ma1 Coeur 1990; 83:1435-g. 8. Malaret GE, Aliaga P. Metastatic disease to the heart. Cancer 1968;22:457-66. 9. Kotler MN. Metastatic cardiac tumors: recognition of pericardial, myocardial and endocardial involvement by two7.
Longitudinal dissociation in the His bundle has been suggested based on experimental studies’ and the finding that distal His bundle pacing in some patients with an electrocardiographic pattern of apparent bundle branch block (BBB) normalizes the ECG. ‘93 We report a case in which a dual His bundle pathway was observed during electrophysiologic study with a left or right BBB pattern depending on which pathway conducted the impulse. A 68-year-old man with a history of hypertension, coronary artery disease, and coronary artery bypass surgery was referred for evaluation of sustained ventricular tachycardia. Physical examination findings were unremarkable, and routine blood chemistry determinations were within normal limits. ECG showed normal sinus rhythm, a normal PR interval, and a normal QRS axis with a nonspecific intraventricular conduction defect. The patient was not taking any cardioactive medication at the time of initial evaluation. Electrophysiologic study was performed with three quadripolar catheters introduced through the right femoral vein and placed in the high right atrium, right ventricular apex, and across the tricuspid
valve for His bundle
re-
cording. During sinus rhythm the AH interval was 70 msec and the HV interval was 70 msec. Atria1 extrastimulus at a basic drive cycle length (BCL) of 600 msec demonstrated a normal QRS pattern at HI-Hz of 410 msec with an Ha-V2 interval of 75 msec (Fig. 1, top panel). At HI-HZ of 400 msec From the Section of Cardiology, Department of Medicine, West Los Angeles Veterans Administration Medical Center and UCLA School of Medicine. Reprint requests: Rafique Ahmed, MD, PhD, Section of Cardiology, Wl llE, West Los Angeles VA Medical Center. Wilshire and Sawtele Blvd., Los Angeles, CA 90073. AM HEART J 1993;125:1784-1786
Copyright
‘, 1993 by Mosby-Year
0002.8703/93/51.00
+ .lO
4/4/45671
Hook.
Inc.