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Contrast echocardiography as an adjunct in hemorrhagic or complicated pericardiocentesis
822
Weisse et al.
4. Rey MJ, Tamm C, Faidutti B, Luthy P, Unger PF. Growth rate of primary left atrial myxoma. Eur Heart J 1993;14:1146-7. 5. Marinissen KI, Essed C, deGroot C, SchellingA, Hagemeijer F. Growth rate of left atrial myxoma. Chest 1987;92:941-2. 6. Meller J, Teichholz LE, Pichard AD, Matta R, Litwak R, Herman MV. Left ventricular myxoma-echocardiographic diagnosis and review of the literature. Am J Med 1977;63:816-23. 7. Otto AC, Hough J. Left ventricular myxoma. S Aft Med J 1989;76:573-4. 8. Wrisley D, Rosenberg J, Giambartolomei A, Levy I, Turiello C, Antonini T. Left ventricular myxoma discovered incidentally by echocardiography. AM HEARTJ 1991;121:1554-5. 9. Abramowitz R, Majdan JF, Plzak LF, Berger B. Two-dimensional echocardiographic diagnosis of separate myxomas of both left atrium and left ventricle. Am J Cardiol 1984;53:379-80.
Contrast echocardiography as an adjunct in hemorrhagic or complicated pericardiocentesis Allen B~ Weisse, MD, Rajendra R. Desai, MD, Gitendra Rajihah, MD, and Santos Lopez, MD Newark, N.J. Two-dimensional echocardiography has proved of great value in the successful performance of pericardiocentesis, with a substantial reduction of associated complications. 1 The use of contrast echocardiography, originally introduced in association with M-mode echocardiography2 and later applied to two-dimensional echocardiography,3 has also proved of assistance in the performance of this procedure. This report of guided pericardiocentesis in conjunction with contrast echocardiography extends these earlier findings with specific reference to instances in which hemorrhagic fluid is obtained on initial sampling. In all three patients reported, pericardiocenteses were performed with two-dimensional echocardiographic guidance for selection of the optimal entry site for the performance of the procedure. An 18-gauge Teflon catheter sheath 6 six inches in length is introduced with a 19gauge needle (Becton-Dickinson long-dwell catheter, Rutherford, N.J.). Immediately on the return of fluid the sheath is advanced as the needle is withdrawn to avoid potential trauma to the heart. Contrast studies are performed with 3 to 7 ml saline solution and approximately 1 ml air, which is agitated by being flushed back and forth between two 10 ml syringes attached to a three-way stopcock before being injected through the pericardiocentesis catheter. Patient 1. This 64-year-old man with a history ofhyper-
From the Department of Medicine, University of Medicine & Dentistry of New Jersey - New Jersey Medical School and University Hospital, Newark. Reprint requests: Allen B. Weisse, MD, Department of Medicine, UMDNJNew Jersey Medical School, 185 South Orange Ave., MSB 1-576, Newark, NJ 07103. AM HEARTJ 1996;131:822-5. Copyright © 1996 by Mosby-Year Book, Inc. 0002-8703/96/$5.00 + 0 4/4/68325
April 1996 American Heart Journal
tension, insulin-dependent diabetes, and gangrene of the right foot was under treatment by hemodialysis for renal failure that had developed after vascular angiographic contrast had been administered in preparation for amputation. Because of increasing shortness of breath an echocardiogram was requested for suspected pericardia] effusion, congestive heart failure, or both. The initial echocardiogram (Fig. 1, A and B), in addition to demonstrating moderate left ventricular systolic dysfunction, showed a large anterior and posterior pericardial effusion with right atrial collapse. The central venous pressure was elevated at 21 mm Hg. A pericardiocentesis was performed through an intercostal space with the exploring needle directed toward the left ventricular apex. No extrasystoles or pulsatile resistance to advancement of the needle occurred. Bloody fluid was obtained on sampling, dripping slowly from the hub of the catheter on removal of the needle. This fluid did not clot on standing, and a sample was sent to the laboratory for hematocrit while a total of I L of fluid was removed. During the aspiration of the fluid the patient reported a relief of symptoms, and at the conclusion of the removal, the systemic blood pressure had risen from 90/60 to 120/80, and the central venous pressure had fallen to 16 mm Hg. However, a repeat echocardiographic study performed immediately after the fluid was removed revealed no apparent reduction in the pericardial effusion. The hematocrit of the fluid removed was reported from the laboratory as 25%; the patient's peripheral blood hematocrit was 26%. A total of 6 ml agitated saline solution was injected through the pericardiocentesis catheter during echocardiographic observation, and this injection revealed filling of the right ventricle (Fig. 1, C). Several beats after the injection, after the intraventricular contrast had disappeared, the catheter, ordinarily not echogenic, was now visible because of the contrast still contained within it (Fig. 1, D). The pressure within the right ventricle measured through the pericardiocentesis catheter was 45/20 mm Hg. The patient was taken to the surgical department for open draining of the pericardial fluid through a pericardial window. The pericardiocentesis catheter was removed under direct observation without subsequent leakage and no need for suturing of the free right ventricular wall. Patient 2. This 37 year-old man had received the diagnosis of the acquired human immunodeficiency syndrome 1 year previously, after Kaposi sarcoma lesions had appeared on his lower extremities. On the current admission he came to the emergency department reporting sudden shortness of breath and retrosternal chest discomfort that had increased over the preceding 3-day period. His blood pressure was 70/40 mm Hg, his heart rate was 122 beats/ minute, and his respiratory rate was 32/minute. Generalized anasarca was present with grossly distended neck veins with the patient sitting upright. A chest radiograph revealed bilateral pleural effusions and a large cardiac silhouette. A two-dimensional echocardiogram revealed a large pericardial effusion and a left pleural effusion (Fig. 2, A). A Swan-Ganz catheter was introduced with the fol-
Volume 131, Number 4
American Heart Journal
Weisse et al.
823
Fig. 1. Patient 1. In A (parasternal long-axis view) and B (apical four-chamber view), large pericardial effusion is demonstrated on two-dimensional echocardiography. In A, w h i t e a r r o w indicates right ventricular cavity, and b l a c k a r r o w indicates posterior pericardial effusion. In C, after injection of agitated saline solution, right ventricle is outlined by echocardiographic contrast. In D, after clearing of echocardiographic contrast from right ventricle, pericardiocentesis catheter, previously not visualized on echocardiography, is now rendered echogenic by contrast material remaining within. lowing pressures obtained in millimeters of mercury: right atrium 19, right ventricle 26/19, pulmonary artery 28/19, and pulmonary capillary wedge 19. Pericardiocentesis was performed via a subcostalparaxiphoid approach. No resistance to the advancement of the needle or extrasystoles was noticed. The bloody fluid obtained did not clot on standing several minutes, and the hematocrit proved to be 18%, similar to that of the patient's peripheral blood (17%). A small bolus (3 ml) of contrast saline solution flushed through the catheter revealed faint visualization of the right ventricle (Fig. 2, B). Because of the patient's critical and deteriorating condition, no delay was deemed advisable. The catheter was gradually withdrawn with multiple small injections of contrast under echocardiographic observation until contrast appeared in the pericardial space (Fig. 2, C and D). On withdrawal of the catheter from the right ventricle to the pericardial space, a few isolated ventricular extrasystoles were observed. A total of 500 ml pericardia] fluid (hematocrit 5%) was removed, with relief of symptoms and reduction in cardiac pressures measured to a mean right atrial and pulmonary capillary wedge pressure level of 9 mm Hg. Alter stabilization was achieved, the patient was taken to the surgical department the next
day for partial pericardiectomy and determination of the presence of angiosarcoma. The pathologic examination revealed fibrinous pericarditis. P a t i e n t 3. This 63-year-old man, who had end-stage renal disease and hypertension and had been under longterm treatment by hemodialysis, was admitted to the hospital with fever and positive blood cultures found on echocardiography to be on the basis of aortic valve infective endocarditis. Moderately severe aortic regurgitation had also developed as a result of this infection. During the course of antibiotic therapy a pericardial friction rub was detected at bedside, and on echocardiography a moderate pericardial effusion was now present (Fig. 3). Although cardiac tamponade was not suspected, a diagnostic pericardiocentesis was deemed advisable to rule out extension of the infection into the pericardial space. A subcostalparaxiphoid approach was used. Bloody fluid was obtained and 6 ml agitated saline solution was injected, confirming the location of the catheter within the pericardial space. The initial sample obtained was later reported to have a hematocrit of 9%, whereas the patient's peripheral blood hematocrit was 29%. The fluid removed was culture-negative for bacteria.
824
Weisse et al.
April 1996 American Heart Journal
Fig. 2. Patient 2. In A, apical four-chamber view reveals large pericardia] effusion (PE) with fibrin strands within. Left pleural effusion (PLE) is also present. In B, after injection ofsmaU amount ofechocardiographic contrast, right ventricle is faintly visualized. C demonstrates visualization of pericardial space after withdrawal of pericardiocentesis catheter from right ventricle and injection of echocardiographic contrast. White arrow points to catheter tip seen on end and made echogenic by echocardiographic contrast within. D indicates fuller delineation of pericardial effusion after larger injection of agitated saline solution. Note that pericardia] effusion is clearly distinguished from adjacent pleura] effusion and that wide dispersal of echocardiographic contrast within pericardial space makes loculation, suspected previously because of large amount of solid material previously noted, highly unlikely.
Fig. 3. Patient 3. Apical four-chamber views demonstrate pericardial effusion adjacent to right ventricle and left ventricular wall (arrows) before (A) and after (B) injection of echocardiographic contrast.
Volume 131, Number 4 American Heart Journal
Pericardial effusions are often hemorrhagic, especially with the large number of patients now undergoing hemodialysis for end-stage renal failure. In the performance of pericardiocenteses in such patients, it is often difficult to determine from appearance alone the source of fluid initially obtained. Even pericardial effusions with a hematocrit level of 10% or less can suggest an intravascular source on gross examination, especially when the patients involved are known to be anemic. Some urgency exists to perform such procedures expeditiously, and laboratory delay in the reporting of hematocrit determinations is variable. Although hemorrhagic pericardial fluid may often not clot on standing, if sufficient protein is present, such may not be the case. Conversely, whole blood from patients on dialysis or with other clotting abnormalities may remain liquid on standing after removal. When contacting the left ventricle the exploring needle will usually transmit pulsations easily detected by the physician. When the left ventricle is penetrated, bright blood is usually obtained and also easily observed as pulsatile in nature, indicating the location. However, blood emerging from the right ventricle, even when the pressures within are abnormally elevated, may drip slowly from the pericardial catheter because of damping during transmission. The low oxygen content may also cause confusion with a peripheral venous source or hemorrhagic pericardial/pleural effusion. As has been noted by others, 2 the right ventricle may be penetrated without perception of resistance by the operator or the warning of extrasystoles. Many of these confounding variables were demonstrated in the patients we report. We were especially misled in patient 1 by his improvement in symptoms and the unexplained rise in systemic blood pressure while he was actually undergoing a significant phlebotomy. The drop in central venous pressure initially observed was obviously caused by hypovolemia rather than relief of cardiac tamponade. Chandraratna et al., ~ in their two-dimensional study of 16 patients undergoing pericardiocentesis with the assistance of contrast echocardiography, emphasized visualization of the pericardial needle during performance of the study. Because of the potential for laceration of the heart associated with the presence of a needle, we recommend rapid withdrawal of the needle and advancement of the flexible •Teflon sheath as soon as fluid is obtained. Echocardiographic contrast can then reveal the site of the catheter tip, and contrast remaining within the catheter lumen renders it echogenic, whereas heretofore we have been unable to visualize this particular catheter on numerous attempts. Once a catheter is located within the right ventricle, we believe that surgical intervention is the wisest course because of some tendency of this chamber to leak after such penetrations, at least experimentally. 4 In patient 2 it was only the critical nature of the patient's status that impelled us to withdraw the catheter from theright ventricle to the pericardial space under emergency conditions, fortunately
1,azogtu et al.
825
without harm. Finally, although not previously demonstrated, we believe that echocardiographic contrast injections performed in association with attempted pericardiocenteses may prove helpful in differentiating sampling from associated pleural effusions versus pericardial effusions. Loculations of pericardial effusions may also potentially be demonstrated with this technique. In conclusion, contrast echocardiography can prove extremely helpful in providing rapid and accurate assessments in the performance of pericardiocenteses when hemorrhagic aspirates are obtained and when the right ventricle has unknowingly been entered. REFERENCES
1. Callahan JA, Seward JR, Nishimura RA, Miller FA Jr, Reeder GS, Shub C, Callahan MJ, Schattenberg TT, Tajik AJ. Two-dimensional echocardiography guided pericardioeentesis: experience in 117 consecutive patients. Am J Cardiol 1985;55:476-9. 2. Chandraratna PAN, First J, Langevin E, O'DeI1R. Echocardiographic contrast studies during pericardiocentesis. Ann Int Med 1977;87:199200. 3. Chandraratna PAN, Reid CL, Nimalasuriya A, Kawanishi D, Rahimtoola SH. Application of two dimensional contrast studies during pericardiocentesis. Am J Cardiol 1983; 52:1120-2. 4. Weisse AB. A new approach for measurement of intrapericardial pressure in the closed chest dog. J Appl PhysioI 1969;26:833-6.
Exercise and heart rate variability Aret H. Lazoglu, MD, Beth Glace, Gilbert W. Gleim, PhD, and Nell L. Coplan, MD New York, N. Y.
The analysis of heart rate variability provides noninvasive information about the autonomic regulation of the heart and may provide important diagnostic and prognostic information in clinical situations such as myocardial infarction.1 Heart rate variability has been shown to be affected by aerobic physical training. 2-4 In this study we compared patients primarily engaging in aerobic •exercise (cyclists) versus those primarily engaging in isometric training (weight lifters) to assess the effect of different types of exercise on 24-hour heart rate variability. Methods. Subjects were <40 years of age and included cyclists (VO2 >55 cc/kg/ml, n = 12), weight lifters (>5 hours of lifting weights per week, n = 10), and a sedentary control group (n = 10). Each subject underwent maximal upright bicycle testing with continuous electrocardiographic monitoring and direct gas exchange measurement for deFrom the Nicholas Institute of Sports Institute and Athletic Training and the Section of Cardiology, Lenox Hill Hospital, New York. Reprint requests: Neff L. Coplan, MD, NISMAT/Lenox Hill Hospital, 130 E. 77th St., New York, NY 10021. AM HEARTJ 1996;131:825-7. Copyright © 1996 by Mosby-Year Book, Inc. 0002-8703/96/$5.00 + 0 4/4/68324
Weisse et al.
4. Rey MJ, Tamm C, Faidutti B, Luthy P, Unger PF. Growth rate of primary left atrial myxoma. Eur Heart J 1993;14:1146-7. 5. Marinissen KI, Essed C, deGroot C, SchellingA, Hagemeijer F. Growth rate of left atrial myxoma. Chest 1987;92:941-2. 6. Meller J, Teichholz LE, Pichard AD, Matta R, Litwak R, Herman MV. Left ventricular myxoma-echocardiographic diagnosis and review of the literature. Am J Med 1977;63:816-23. 7. Otto AC, Hough J. Left ventricular myxoma. S Aft Med J 1989;76:573-4. 8. Wrisley D, Rosenberg J, Giambartolomei A, Levy I, Turiello C, Antonini T. Left ventricular myxoma discovered incidentally by echocardiography. AM HEARTJ 1991;121:1554-5. 9. Abramowitz R, Majdan JF, Plzak LF, Berger B. Two-dimensional echocardiographic diagnosis of separate myxomas of both left atrium and left ventricle. Am J Cardiol 1984;53:379-80.
Contrast echocardiography as an adjunct in hemorrhagic or complicated pericardiocentesis Allen B~ Weisse, MD, Rajendra R. Desai, MD, Gitendra Rajihah, MD, and Santos Lopez, MD Newark, N.J. Two-dimensional echocardiography has proved of great value in the successful performance of pericardiocentesis, with a substantial reduction of associated complications. 1 The use of contrast echocardiography, originally introduced in association with M-mode echocardiography2 and later applied to two-dimensional echocardiography,3 has also proved of assistance in the performance of this procedure. This report of guided pericardiocentesis in conjunction with contrast echocardiography extends these earlier findings with specific reference to instances in which hemorrhagic fluid is obtained on initial sampling. In all three patients reported, pericardiocenteses were performed with two-dimensional echocardiographic guidance for selection of the optimal entry site for the performance of the procedure. An 18-gauge Teflon catheter sheath 6 six inches in length is introduced with a 19gauge needle (Becton-Dickinson long-dwell catheter, Rutherford, N.J.). Immediately on the return of fluid the sheath is advanced as the needle is withdrawn to avoid potential trauma to the heart. Contrast studies are performed with 3 to 7 ml saline solution and approximately 1 ml air, which is agitated by being flushed back and forth between two 10 ml syringes attached to a three-way stopcock before being injected through the pericardiocentesis catheter. Patient 1. This 64-year-old man with a history ofhyper-
From the Department of Medicine, University of Medicine & Dentistry of New Jersey - New Jersey Medical School and University Hospital, Newark. Reprint requests: Allen B. Weisse, MD, Department of Medicine, UMDNJNew Jersey Medical School, 185 South Orange Ave., MSB 1-576, Newark, NJ 07103. AM HEARTJ 1996;131:822-5. Copyright © 1996 by Mosby-Year Book, Inc. 0002-8703/96/$5.00 + 0 4/4/68325
April 1996 American Heart Journal
tension, insulin-dependent diabetes, and gangrene of the right foot was under treatment by hemodialysis for renal failure that had developed after vascular angiographic contrast had been administered in preparation for amputation. Because of increasing shortness of breath an echocardiogram was requested for suspected pericardia] effusion, congestive heart failure, or both. The initial echocardiogram (Fig. 1, A and B), in addition to demonstrating moderate left ventricular systolic dysfunction, showed a large anterior and posterior pericardial effusion with right atrial collapse. The central venous pressure was elevated at 21 mm Hg. A pericardiocentesis was performed through an intercostal space with the exploring needle directed toward the left ventricular apex. No extrasystoles or pulsatile resistance to advancement of the needle occurred. Bloody fluid was obtained on sampling, dripping slowly from the hub of the catheter on removal of the needle. This fluid did not clot on standing, and a sample was sent to the laboratory for hematocrit while a total of I L of fluid was removed. During the aspiration of the fluid the patient reported a relief of symptoms, and at the conclusion of the removal, the systemic blood pressure had risen from 90/60 to 120/80, and the central venous pressure had fallen to 16 mm Hg. However, a repeat echocardiographic study performed immediately after the fluid was removed revealed no apparent reduction in the pericardial effusion. The hematocrit of the fluid removed was reported from the laboratory as 25%; the patient's peripheral blood hematocrit was 26%. A total of 6 ml agitated saline solution was injected through the pericardiocentesis catheter during echocardiographic observation, and this injection revealed filling of the right ventricle (Fig. 1, C). Several beats after the injection, after the intraventricular contrast had disappeared, the catheter, ordinarily not echogenic, was now visible because of the contrast still contained within it (Fig. 1, D). The pressure within the right ventricle measured through the pericardiocentesis catheter was 45/20 mm Hg. The patient was taken to the surgical department for open draining of the pericardial fluid through a pericardial window. The pericardiocentesis catheter was removed under direct observation without subsequent leakage and no need for suturing of the free right ventricular wall. Patient 2. This 37 year-old man had received the diagnosis of the acquired human immunodeficiency syndrome 1 year previously, after Kaposi sarcoma lesions had appeared on his lower extremities. On the current admission he came to the emergency department reporting sudden shortness of breath and retrosternal chest discomfort that had increased over the preceding 3-day period. His blood pressure was 70/40 mm Hg, his heart rate was 122 beats/ minute, and his respiratory rate was 32/minute. Generalized anasarca was present with grossly distended neck veins with the patient sitting upright. A chest radiograph revealed bilateral pleural effusions and a large cardiac silhouette. A two-dimensional echocardiogram revealed a large pericardial effusion and a left pleural effusion (Fig. 2, A). A Swan-Ganz catheter was introduced with the fol-
Volume 131, Number 4
American Heart Journal
Weisse et al.
823
Fig. 1. Patient 1. In A (parasternal long-axis view) and B (apical four-chamber view), large pericardial effusion is demonstrated on two-dimensional echocardiography. In A, w h i t e a r r o w indicates right ventricular cavity, and b l a c k a r r o w indicates posterior pericardial effusion. In C, after injection of agitated saline solution, right ventricle is outlined by echocardiographic contrast. In D, after clearing of echocardiographic contrast from right ventricle, pericardiocentesis catheter, previously not visualized on echocardiography, is now rendered echogenic by contrast material remaining within. lowing pressures obtained in millimeters of mercury: right atrium 19, right ventricle 26/19, pulmonary artery 28/19, and pulmonary capillary wedge 19. Pericardiocentesis was performed via a subcostalparaxiphoid approach. No resistance to the advancement of the needle or extrasystoles was noticed. The bloody fluid obtained did not clot on standing several minutes, and the hematocrit proved to be 18%, similar to that of the patient's peripheral blood (17%). A small bolus (3 ml) of contrast saline solution flushed through the catheter revealed faint visualization of the right ventricle (Fig. 2, B). Because of the patient's critical and deteriorating condition, no delay was deemed advisable. The catheter was gradually withdrawn with multiple small injections of contrast under echocardiographic observation until contrast appeared in the pericardial space (Fig. 2, C and D). On withdrawal of the catheter from the right ventricle to the pericardial space, a few isolated ventricular extrasystoles were observed. A total of 500 ml pericardia] fluid (hematocrit 5%) was removed, with relief of symptoms and reduction in cardiac pressures measured to a mean right atrial and pulmonary capillary wedge pressure level of 9 mm Hg. Alter stabilization was achieved, the patient was taken to the surgical department the next
day for partial pericardiectomy and determination of the presence of angiosarcoma. The pathologic examination revealed fibrinous pericarditis. P a t i e n t 3. This 63-year-old man, who had end-stage renal disease and hypertension and had been under longterm treatment by hemodialysis, was admitted to the hospital with fever and positive blood cultures found on echocardiography to be on the basis of aortic valve infective endocarditis. Moderately severe aortic regurgitation had also developed as a result of this infection. During the course of antibiotic therapy a pericardial friction rub was detected at bedside, and on echocardiography a moderate pericardial effusion was now present (Fig. 3). Although cardiac tamponade was not suspected, a diagnostic pericardiocentesis was deemed advisable to rule out extension of the infection into the pericardial space. A subcostalparaxiphoid approach was used. Bloody fluid was obtained and 6 ml agitated saline solution was injected, confirming the location of the catheter within the pericardial space. The initial sample obtained was later reported to have a hematocrit of 9%, whereas the patient's peripheral blood hematocrit was 29%. The fluid removed was culture-negative for bacteria.
824
Weisse et al.
April 1996 American Heart Journal
Fig. 2. Patient 2. In A, apical four-chamber view reveals large pericardia] effusion (PE) with fibrin strands within. Left pleural effusion (PLE) is also present. In B, after injection ofsmaU amount ofechocardiographic contrast, right ventricle is faintly visualized. C demonstrates visualization of pericardial space after withdrawal of pericardiocentesis catheter from right ventricle and injection of echocardiographic contrast. White arrow points to catheter tip seen on end and made echogenic by echocardiographic contrast within. D indicates fuller delineation of pericardial effusion after larger injection of agitated saline solution. Note that pericardia] effusion is clearly distinguished from adjacent pleura] effusion and that wide dispersal of echocardiographic contrast within pericardial space makes loculation, suspected previously because of large amount of solid material previously noted, highly unlikely.
Fig. 3. Patient 3. Apical four-chamber views demonstrate pericardial effusion adjacent to right ventricle and left ventricular wall (arrows) before (A) and after (B) injection of echocardiographic contrast.
Volume 131, Number 4 American Heart Journal
Pericardial effusions are often hemorrhagic, especially with the large number of patients now undergoing hemodialysis for end-stage renal failure. In the performance of pericardiocenteses in such patients, it is often difficult to determine from appearance alone the source of fluid initially obtained. Even pericardial effusions with a hematocrit level of 10% or less can suggest an intravascular source on gross examination, especially when the patients involved are known to be anemic. Some urgency exists to perform such procedures expeditiously, and laboratory delay in the reporting of hematocrit determinations is variable. Although hemorrhagic pericardial fluid may often not clot on standing, if sufficient protein is present, such may not be the case. Conversely, whole blood from patients on dialysis or with other clotting abnormalities may remain liquid on standing after removal. When contacting the left ventricle the exploring needle will usually transmit pulsations easily detected by the physician. When the left ventricle is penetrated, bright blood is usually obtained and also easily observed as pulsatile in nature, indicating the location. However, blood emerging from the right ventricle, even when the pressures within are abnormally elevated, may drip slowly from the pericardial catheter because of damping during transmission. The low oxygen content may also cause confusion with a peripheral venous source or hemorrhagic pericardial/pleural effusion. As has been noted by others, 2 the right ventricle may be penetrated without perception of resistance by the operator or the warning of extrasystoles. Many of these confounding variables were demonstrated in the patients we report. We were especially misled in patient 1 by his improvement in symptoms and the unexplained rise in systemic blood pressure while he was actually undergoing a significant phlebotomy. The drop in central venous pressure initially observed was obviously caused by hypovolemia rather than relief of cardiac tamponade. Chandraratna et al., ~ in their two-dimensional study of 16 patients undergoing pericardiocentesis with the assistance of contrast echocardiography, emphasized visualization of the pericardial needle during performance of the study. Because of the potential for laceration of the heart associated with the presence of a needle, we recommend rapid withdrawal of the needle and advancement of the flexible •Teflon sheath as soon as fluid is obtained. Echocardiographic contrast can then reveal the site of the catheter tip, and contrast remaining within the catheter lumen renders it echogenic, whereas heretofore we have been unable to visualize this particular catheter on numerous attempts. Once a catheter is located within the right ventricle, we believe that surgical intervention is the wisest course because of some tendency of this chamber to leak after such penetrations, at least experimentally. 4 In patient 2 it was only the critical nature of the patient's status that impelled us to withdraw the catheter from theright ventricle to the pericardial space under emergency conditions, fortunately
1,azogtu et al.
825
without harm. Finally, although not previously demonstrated, we believe that echocardiographic contrast injections performed in association with attempted pericardiocenteses may prove helpful in differentiating sampling from associated pleural effusions versus pericardial effusions. Loculations of pericardial effusions may also potentially be demonstrated with this technique. In conclusion, contrast echocardiography can prove extremely helpful in providing rapid and accurate assessments in the performance of pericardiocenteses when hemorrhagic aspirates are obtained and when the right ventricle has unknowingly been entered. REFERENCES
1. Callahan JA, Seward JR, Nishimura RA, Miller FA Jr, Reeder GS, Shub C, Callahan MJ, Schattenberg TT, Tajik AJ. Two-dimensional echocardiography guided pericardioeentesis: experience in 117 consecutive patients. Am J Cardiol 1985;55:476-9. 2. Chandraratna PAN, First J, Langevin E, O'DeI1R. Echocardiographic contrast studies during pericardiocentesis. Ann Int Med 1977;87:199200. 3. Chandraratna PAN, Reid CL, Nimalasuriya A, Kawanishi D, Rahimtoola SH. Application of two dimensional contrast studies during pericardiocentesis. Am J Cardiol 1983; 52:1120-2. 4. Weisse AB. A new approach for measurement of intrapericardial pressure in the closed chest dog. J Appl PhysioI 1969;26:833-6.
Exercise and heart rate variability Aret H. Lazoglu, MD, Beth Glace, Gilbert W. Gleim, PhD, and Nell L. Coplan, MD New York, N. Y.
The analysis of heart rate variability provides noninvasive information about the autonomic regulation of the heart and may provide important diagnostic and prognostic information in clinical situations such as myocardial infarction.1 Heart rate variability has been shown to be affected by aerobic physical training. 2-4 In this study we compared patients primarily engaging in aerobic •exercise (cyclists) versus those primarily engaging in isometric training (weight lifters) to assess the effect of different types of exercise on 24-hour heart rate variability. Methods. Subjects were <40 years of age and included cyclists (VO2 >55 cc/kg/ml, n = 12), weight lifters (>5 hours of lifting weights per week, n = 10), and a sedentary control group (n = 10). Each subject underwent maximal upright bicycle testing with continuous electrocardiographic monitoring and direct gas exchange measurement for deFrom the Nicholas Institute of Sports Institute and Athletic Training and the Section of Cardiology, Lenox Hill Hospital, New York. Reprint requests: Neff L. Coplan, MD, NISMAT/Lenox Hill Hospital, 130 E. 77th St., New York, NY 10021. AM HEARTJ 1996;131:825-7. Copyright © 1996 by Mosby-Year Book, Inc. 0002-8703/96/$5.00 + 0 4/4/68324