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EVALUATION OF CARDIAC FUNCTION BY SUPRASTERNAL PUNCTURE
E V A L U A T I O N OF CARDIAC F U N C T I O N B Y SUPRASTERNAL PUNCTURE Vallée L. Willman, N. Symbas, M.D.
M.D. (by invitation), (by invitation),
C. Rollins Hanion, M.D.,
John ]. Kelly, M.D.
]. Gerard Mudd, M.D. (by invitation),
St. Louis,
Panagiotis
(by invitation),
and
Mo.
T
HE value of recording the left atrial pressure and wave forms is well es tablished in the assessment of patients with mitral valve disease.3· β· " ■ 1 3 ' 1 4 Most techniques for left atrial catheterization are cumbersome and complicated in contrast to the simple suprasternal puncture described by Kadner. 16 The lack of widespread and enthusiastic acceptance of the Radner method might suggest some inherent deficiencies in the technique; our experience in 280 instances demonstrates its safety and practicality. METHODS
With the patient supine and the head extended, the neck and upper sternum is cleansed and draped for infiltration of the suprasternal notch with one per cent procaine. This infiltration is carried down to the sternoclavicular ligament. A 6 inch, 21-gauge needle is introduced retrosternally at a 40 degree angle to the anterior chest and pointing slightly to the left of the mid-line. One advances the needle steadily to puncture and traverse serially the aorta, pulmonary artery, and superior wall of the left atrium (Fig. 1). A strain gauge and recorder system of high frequency response permits recording of pressure and pulse forms from these three areas. Blood samples may be taken for gas analysis as the needle is withdrawn. RESULTS
The test has been performed in 280 instances, in 34 of which there was a complementary percutaneous puncture of the left ventricle at the apex using a 21-gauge, 2 inch needle as described by Brock.2 Most of the patients were in their third or fourth decade; ages ranged from 5 to 62 years. Two hundred Prom the Department of Surgery, The Cardiac Catheterization Laboratory of the Depart ment of Internal Medicine and the Center for Cardiovascular Research, St. Louis University, St. Louis, Mo. Aided by grants from The John A. Hartford Foundation and U. S. Public Health Service HE-06312, HE-5299-06, and HE-3826-06. Read at the Forty-fourth Annual Meeting· of The American Association for Thoracic Surgery, Montreal, Canada, April 27, 28, and 29, 1964. 959
WILLMAN ET AL.
960
J. Thoracic and Cardiovas. Surg.
and seventy studies were for assessment of rheumatic heart disease, 5 were for assessment of congenital heart disease, 3 for differential diganosis between pulmonary embolism and myocardial infarction, and 2 for measurement of pulmonary arterial pressure in previously diagnosed primary pulmonary hypertension. In 14 of the 280 instances, the left atrium was not entered; a failure rate of 5 per cent. The pulmonary artery was not entered in 40 instances (14 per cent). The aorta was not entered in 17 per cent (Table I ) .
Fig. 1.—The course of the needle in suprasternal puncture is through the aorta (A), pul monary artery (PA), and left atrium (LA). The free pleural or pericardial space is generally not entered. TABLE I.
SUPRASTERNAL
CHAMBER ENTERED Left atrium Pulmonary artery Aorta
PUNCTURE
(280
|
PROCEDURES)
| 266 240 232
95% 86% 83%
A feeling of "stickiness in the throat" was experienced by most patients. Substernal pain requiring medication was present in 32 patients. None had this discomfort for longer than 36 hours. Three experienced nausea and vomit ing, 4 had transient hypotension not requiring treatment. Of those patients who
Vol. 48, No. 6
December, 1964
T E S T FOB CAEDIAC F U N C T I O N
961
had both suprasternal and ventricular punctures, 1 had hemoptysis and 1 had a pneumothorax requiring a single aspiration. Temperature elevation to a level of 101°F. occurred in 2 patients (Table I I ) .
TABLE I I .
Chest pain Hypotension Nausea and emesis Bradycardia Shortness of breath Hyperpyrexia Hemoptysis Pneumothorax Death
SUPRASTERNAL
PUNCTURE:
COMPLICATIONS
IN 280
SUPRASTERNAL PUNCTURE ALONE
W I T H VENTRICULAR PUNCTURE
(241) 32 4
(39) 8
o
3 2
2 1 1 1
INSTANCES
TOTAL
(280) 40 4 3 3 2 2 1 1 1
Death occurred within a week of catheterization in two instances. Details of these fatal cases are as follows: A 52-year-old man with calcifié aortic stenosis had suprasternal puncture of the aorta, pulmonary artery, and left atrium; this was followed immediately by percutaneous left ventricular puncture. Recorded pressures in millimeter of mercury were: aorta, 85/58; left ventricle, 140/0; pulmonary artery, 72/31; left atrium, ac 31, v 40, y 11. After the procedure he experienced substernal pain and became hypotensive. Progressive pulmonary edema ensued and he died 25 hours later. Autopsy disclosed severe calcifié aortic stenosis and arteriosclerotic coronary artery disease with ascites and pleural fluid. There was 100 c.c. of bloody fluid in the pericardial sac. The path of the suprasternal needle puncture led directly through the aorta and pulmonary artery into the left atrium. It was not a source of bleeding into the pericardium. No coronary vessels were lacerated by the ventricular puncture. Death was attributed to myocardial ischemia secondary to aortic stenosis and coronary atherosclerosis. A 53-year-old woman had suprasternal puncture of the aorta, pulmonary artery, and left atrium to assist in evaluation of her cardiac status 4 years after mitral valvotomy which had originally improved her functional classification from class I I I to class II. She had been admitted to the hospital for hemorrhoidectomy. On catheterization, the measured pressures in millimeters of mercury were: aorta, 144/68; pulmonary artery, 50/23; left atrium, ac 26, v 45, y 13. She went home 24 hours after catheterization. Two days later, she was found dead. The body was obtained following embalming. There was no blood in the pleural or pericardial spaces. There was a scalp laceration and hematoma where she had struck her head on a radiator. The exact cause of her death was not determined and cannot certainly be related to the catheterization.
962
W I L L M A N E T AL.
J. Thoracic and Cardiovas. Surg.
DISCUSSION
The simplicity of the Radner technique is its most striking feature. The entire procedure is generally accomplished in less than 15 minutes, with only minor inconvenience and discomfort to the patient. Fluoroscopy is not employed. The ostensible hazard of traversing the aorta and pulmonary artery to puncture the left atrium is not borne out by our experience. The safety of the procedure is probably related to the use of a small gauge needle which remains entirely within the mediastinum and generally does not traverse the free pericardial or pleural space. The incidence of complications is less than that reported with other techniques. 1 ' 8 ' 9 · 1 2 ' 1 5 ' 2 l · 2 3 A limitation of the suprasternal procedure is the inability to obtain left ventricular pressure. This restriction can be obviated either by separate left ventricular puncture, as we have done in 39 instances, or by using a larger needle to allow passage of a catheter through it into the atrium and ventricle. Both of these variations increase the risk of the procedure; they should be limited to instances where it is considered essential to determine the pressure gradient between the left atrium and left ventricle during diastole. The success rate of 95 per cent in obtaining atrial pressure and 86 per cent for pulmonary arterial pressure compares favorably with our experience in 100 transbronchial catheterizations. By the transbronchial technique, we were successful in obtaining left atrial pressure in 95 per cent and pulmonary artery pressure in 35 per cent. Even with the transbronchial method we were able to introduce a catheter into the left ventricle in only 39 per cent of the attempts (Table I I I ) .
TABLE I I I .
100
CHAMBER ENTERED
Left atrium Pulmonary artery Left ventricle (catheter)
TRANSBRONCHIAL CATHETERIZATIONS |
INCIDENCE
95% 35% 39%
High fever was common after transbronchial catheterization 24 and many patients complained bitterly of postoperative discomfort which made them un willing to have further similar tests. Patients who have undergone suprasternal puncture, on the other hand, are quite willing to accept repeated investigation. Twenty-one patients have been catheterized on two or more occasions. Radner has adequately described the technique 16 and indicated its ap plicability in a number of conditions. 4 ' 10 ' 17 " 20 Greene and associates similarly have discussed its applicability and simplicity. 5 Hansen and co-workers7 reported 500 instances without serious complication. The technique, however, has not been widely adopted and one recent survey of catheterization methods failed to discuss it.22 The present experience may serve to emphasize its utility and relative safety.
Vol. 48. No. 6
TEST FOR CARDIAC F U N C T I O N
963
December, 1964 SUMMARY
Suprasternal, percutaneous puncture of the aorta, pulmonary artery, and left atrium has been performed in 280 instances with a high incidence of success and a low incidence of morbidity. The usefulness and simplicity of the technique argue for its wider acceptance. REFERENCES
1. Androuny, Z. A., Sutherland, D. W., Griswold, H. E., and Ritzmann, L. W. : Complications With Transseptal Left Heart Catheterization, Am. Heart J . 65: 327, 1963. 2. Brock, R., Milstein, B . B., and Ross, D. H. : Percutaneous Left Ventricular Puncture in the Assessment of Aortic Stenosis, Thorax 1 1 : 163, 1956. 3. Brockenbrough, E. C , Braunwald, É., and Ross, J., J r . : Transseptal Left Heart Catheteri zation, Circulation 25: 15, 1962. 4. Dahlback, O., and Radner, S. : Suprasternal Pressure Curves in Combined Aortic and Mitral Valvular Disease, Acta chir. scandinav. 109: 310, 1955. 5. Greene, D. G., Sharp, J . T., Griffith, G. T., Bunnell, J . L., and MacManus, J . E . : Surgical Applications of Anterior Percutaneous Left Atrial Puncture, Surgery 4 3 : 1, 1958. 6. Fisher, D. L. : The Use of Pressure Recordings Obtained at Transthoracie Left Heart Catheterization in the Diagnosis of Valvular Heart Disease, J . THORACIC SURG. 30: 379, 1955. 7. Hansen, A. T., Fabricius, F., Pedersen, A., and Sande, E. : Suprasternal Puncture of the Left Atrium and the Great Vessels: Experience From 500 Punctures, Am. Heart J . 63: 443, 1962. 8. Kavanagh-Gray, D., and Drake, E. H . : Complications of Left H e a r t Catheterizations Using the Right Transthoracie Approach, Am. Heart J . 56: 143, 1958. 9. Leach, J . K., Friedlieh, A. L., Myers, G. S., Sanders, C. A., and Scanneil, J . G. : Useful ness and Limitations of Left Heart Catheterization in Mitral Disease, Am. J . Cardiol. 10: 57, 1962. 10. Linder, E., Radner, S., Gustafson, A., Edler, I., and Dahlback, O. : Suprasternal Pressure Curves in Constrietive Pericarditis, Acta med. scandinav. 155: 431, 1956. 11. Marshall, H. W., Woodward, E., Jr., and Wood, E . H . : Hemodynamic Methods for Differentiation of Mitral Stenosis and Régurgitation, Am. J . Cardiol. 2 : 24, 1958. 12. Mclntosh, H. D., Whalen, R. E., Hernandez, R. R., Morris, J . J., and Miller, D. E. : Potential Hazard of Transseptal Left Atrial Catheterization Technique, Am. J . Cardiol. 8: 835, 1961. 13. Morrow, A. G., Braunwald, E., Haller, J . A., and Sharp, E. H. : Left Atrial Pressure Pulse in Mitral Valve Disease, Circulation 16: 399, 1957. 14. Neustadt, J . E., and Shaffer, A. B . : Diagnostic Value of the Left Atrial Pressure Pulse in Mitral Valvular Disease, Am. Heart J . 58: 675, 1959. 15. Musser, B. G., and Goldberg, H. : Left Heart Catheterization. J . THORACIC SURG. 34: 414, 1957. 16. Radner, S. Extended Suprasternal Puncture Technique, Acta med. scandinav. 151: 223, 1955. 17. Radner, S.: Suprasternal Pressure Curves in Mitral Insufficiency, Acta med. scandinav. 152: 1, 1955. 18. Radner, S. : Atrioventricular Activity as Reflected in Suprasternal Pressure Curves, Acta med. scandinav. 164: 1, 1959. 19. Radner, S., Edler, L, and Gustafson, A.: Suprasternal Pressure Curves in Atrial Flutter, Acta med. scandinav. 152: 271, 1955. 20. Radner, S., Erland, L., Dahlback, O., Edler, I., and Gustafson, A.: Suprasternal Pressure Curves in Early Mitral Stenosis, Acta med. scandinav. 154: 299, 1956. 21. Russell, R. O., Carroll, J . F., and Hood, W. G., J r . : Cardiac Tamponade: A Complication of the Technique of Left Heart Catheterization Resulting in a Fatality, Am. J . Cardiol. 13: 558, 1964. 22. Selzer, A., Popper, R. W., Lau, F . Y. K., Morgan, J . J., and Anderson, W. L.: Present Status of Diagnostic Cardiac Catheterization, New England J . Med. 268: 589 and 654, 1963. 23. Susmano, A. and Carleton, R. A.: Transseptal Catheterization of the Left Atrium: Report of an Unusual Complication, New England J . Med. 270: 897, 1964. 24. Willman, V. L., Mudd, J . G., Nigh, C. A., and Hanlon, C. R. : Left Heart Catheterization, Missouri Med. 55: 225, 1958. (For Discussion, see page 979)
M.D. (by invitation), (by invitation),
C. Rollins Hanion, M.D.,
John ]. Kelly, M.D.
]. Gerard Mudd, M.D. (by invitation),
St. Louis,
Panagiotis
(by invitation),
and
Mo.
T
HE value of recording the left atrial pressure and wave forms is well es tablished in the assessment of patients with mitral valve disease.3· β· " ■ 1 3 ' 1 4 Most techniques for left atrial catheterization are cumbersome and complicated in contrast to the simple suprasternal puncture described by Kadner. 16 The lack of widespread and enthusiastic acceptance of the Radner method might suggest some inherent deficiencies in the technique; our experience in 280 instances demonstrates its safety and practicality. METHODS
With the patient supine and the head extended, the neck and upper sternum is cleansed and draped for infiltration of the suprasternal notch with one per cent procaine. This infiltration is carried down to the sternoclavicular ligament. A 6 inch, 21-gauge needle is introduced retrosternally at a 40 degree angle to the anterior chest and pointing slightly to the left of the mid-line. One advances the needle steadily to puncture and traverse serially the aorta, pulmonary artery, and superior wall of the left atrium (Fig. 1). A strain gauge and recorder system of high frequency response permits recording of pressure and pulse forms from these three areas. Blood samples may be taken for gas analysis as the needle is withdrawn. RESULTS
The test has been performed in 280 instances, in 34 of which there was a complementary percutaneous puncture of the left ventricle at the apex using a 21-gauge, 2 inch needle as described by Brock.2 Most of the patients were in their third or fourth decade; ages ranged from 5 to 62 years. Two hundred Prom the Department of Surgery, The Cardiac Catheterization Laboratory of the Depart ment of Internal Medicine and the Center for Cardiovascular Research, St. Louis University, St. Louis, Mo. Aided by grants from The John A. Hartford Foundation and U. S. Public Health Service HE-06312, HE-5299-06, and HE-3826-06. Read at the Forty-fourth Annual Meeting· of The American Association for Thoracic Surgery, Montreal, Canada, April 27, 28, and 29, 1964. 959
WILLMAN ET AL.
960
J. Thoracic and Cardiovas. Surg.
and seventy studies were for assessment of rheumatic heart disease, 5 were for assessment of congenital heart disease, 3 for differential diganosis between pulmonary embolism and myocardial infarction, and 2 for measurement of pulmonary arterial pressure in previously diagnosed primary pulmonary hypertension. In 14 of the 280 instances, the left atrium was not entered; a failure rate of 5 per cent. The pulmonary artery was not entered in 40 instances (14 per cent). The aorta was not entered in 17 per cent (Table I ) .
Fig. 1.—The course of the needle in suprasternal puncture is through the aorta (A), pul monary artery (PA), and left atrium (LA). The free pleural or pericardial space is generally not entered. TABLE I.
SUPRASTERNAL
CHAMBER ENTERED Left atrium Pulmonary artery Aorta
PUNCTURE
(280
|
PROCEDURES)
| 266 240 232
95% 86% 83%
A feeling of "stickiness in the throat" was experienced by most patients. Substernal pain requiring medication was present in 32 patients. None had this discomfort for longer than 36 hours. Three experienced nausea and vomit ing, 4 had transient hypotension not requiring treatment. Of those patients who
Vol. 48, No. 6
December, 1964
T E S T FOB CAEDIAC F U N C T I O N
961
had both suprasternal and ventricular punctures, 1 had hemoptysis and 1 had a pneumothorax requiring a single aspiration. Temperature elevation to a level of 101°F. occurred in 2 patients (Table I I ) .
TABLE I I .
Chest pain Hypotension Nausea and emesis Bradycardia Shortness of breath Hyperpyrexia Hemoptysis Pneumothorax Death
SUPRASTERNAL
PUNCTURE:
COMPLICATIONS
IN 280
SUPRASTERNAL PUNCTURE ALONE
W I T H VENTRICULAR PUNCTURE
(241) 32 4
(39) 8
o
3 2
2 1 1 1
INSTANCES
TOTAL
(280) 40 4 3 3 2 2 1 1 1
Death occurred within a week of catheterization in two instances. Details of these fatal cases are as follows: A 52-year-old man with calcifié aortic stenosis had suprasternal puncture of the aorta, pulmonary artery, and left atrium; this was followed immediately by percutaneous left ventricular puncture. Recorded pressures in millimeter of mercury were: aorta, 85/58; left ventricle, 140/0; pulmonary artery, 72/31; left atrium, ac 31, v 40, y 11. After the procedure he experienced substernal pain and became hypotensive. Progressive pulmonary edema ensued and he died 25 hours later. Autopsy disclosed severe calcifié aortic stenosis and arteriosclerotic coronary artery disease with ascites and pleural fluid. There was 100 c.c. of bloody fluid in the pericardial sac. The path of the suprasternal needle puncture led directly through the aorta and pulmonary artery into the left atrium. It was not a source of bleeding into the pericardium. No coronary vessels were lacerated by the ventricular puncture. Death was attributed to myocardial ischemia secondary to aortic stenosis and coronary atherosclerosis. A 53-year-old woman had suprasternal puncture of the aorta, pulmonary artery, and left atrium to assist in evaluation of her cardiac status 4 years after mitral valvotomy which had originally improved her functional classification from class I I I to class II. She had been admitted to the hospital for hemorrhoidectomy. On catheterization, the measured pressures in millimeters of mercury were: aorta, 144/68; pulmonary artery, 50/23; left atrium, ac 26, v 45, y 13. She went home 24 hours after catheterization. Two days later, she was found dead. The body was obtained following embalming. There was no blood in the pleural or pericardial spaces. There was a scalp laceration and hematoma where she had struck her head on a radiator. The exact cause of her death was not determined and cannot certainly be related to the catheterization.
962
W I L L M A N E T AL.
J. Thoracic and Cardiovas. Surg.
DISCUSSION
The simplicity of the Radner technique is its most striking feature. The entire procedure is generally accomplished in less than 15 minutes, with only minor inconvenience and discomfort to the patient. Fluoroscopy is not employed. The ostensible hazard of traversing the aorta and pulmonary artery to puncture the left atrium is not borne out by our experience. The safety of the procedure is probably related to the use of a small gauge needle which remains entirely within the mediastinum and generally does not traverse the free pericardial or pleural space. The incidence of complications is less than that reported with other techniques. 1 ' 8 ' 9 · 1 2 ' 1 5 ' 2 l · 2 3 A limitation of the suprasternal procedure is the inability to obtain left ventricular pressure. This restriction can be obviated either by separate left ventricular puncture, as we have done in 39 instances, or by using a larger needle to allow passage of a catheter through it into the atrium and ventricle. Both of these variations increase the risk of the procedure; they should be limited to instances where it is considered essential to determine the pressure gradient between the left atrium and left ventricle during diastole. The success rate of 95 per cent in obtaining atrial pressure and 86 per cent for pulmonary arterial pressure compares favorably with our experience in 100 transbronchial catheterizations. By the transbronchial technique, we were successful in obtaining left atrial pressure in 95 per cent and pulmonary artery pressure in 35 per cent. Even with the transbronchial method we were able to introduce a catheter into the left ventricle in only 39 per cent of the attempts (Table I I I ) .
TABLE I I I .
100
CHAMBER ENTERED
Left atrium Pulmonary artery Left ventricle (catheter)
TRANSBRONCHIAL CATHETERIZATIONS |
INCIDENCE
95% 35% 39%
High fever was common after transbronchial catheterization 24 and many patients complained bitterly of postoperative discomfort which made them un willing to have further similar tests. Patients who have undergone suprasternal puncture, on the other hand, are quite willing to accept repeated investigation. Twenty-one patients have been catheterized on two or more occasions. Radner has adequately described the technique 16 and indicated its ap plicability in a number of conditions. 4 ' 10 ' 17 " 20 Greene and associates similarly have discussed its applicability and simplicity. 5 Hansen and co-workers7 reported 500 instances without serious complication. The technique, however, has not been widely adopted and one recent survey of catheterization methods failed to discuss it.22 The present experience may serve to emphasize its utility and relative safety.
Vol. 48. No. 6
TEST FOR CARDIAC F U N C T I O N
963
December, 1964 SUMMARY
Suprasternal, percutaneous puncture of the aorta, pulmonary artery, and left atrium has been performed in 280 instances with a high incidence of success and a low incidence of morbidity. The usefulness and simplicity of the technique argue for its wider acceptance. REFERENCES
1. Androuny, Z. A., Sutherland, D. W., Griswold, H. E., and Ritzmann, L. W. : Complications With Transseptal Left Heart Catheterization, Am. Heart J . 65: 327, 1963. 2. Brock, R., Milstein, B . B., and Ross, D. H. : Percutaneous Left Ventricular Puncture in the Assessment of Aortic Stenosis, Thorax 1 1 : 163, 1956. 3. Brockenbrough, E. C , Braunwald, É., and Ross, J., J r . : Transseptal Left Heart Catheteri zation, Circulation 25: 15, 1962. 4. Dahlback, O., and Radner, S. : Suprasternal Pressure Curves in Combined Aortic and Mitral Valvular Disease, Acta chir. scandinav. 109: 310, 1955. 5. Greene, D. G., Sharp, J . T., Griffith, G. T., Bunnell, J . L., and MacManus, J . E . : Surgical Applications of Anterior Percutaneous Left Atrial Puncture, Surgery 4 3 : 1, 1958. 6. Fisher, D. L. : The Use of Pressure Recordings Obtained at Transthoracie Left Heart Catheterization in the Diagnosis of Valvular Heart Disease, J . THORACIC SURG. 30: 379, 1955. 7. Hansen, A. T., Fabricius, F., Pedersen, A., and Sande, E. : Suprasternal Puncture of the Left Atrium and the Great Vessels: Experience From 500 Punctures, Am. Heart J . 63: 443, 1962. 8. Kavanagh-Gray, D., and Drake, E. H . : Complications of Left H e a r t Catheterizations Using the Right Transthoracie Approach, Am. Heart J . 56: 143, 1958. 9. Leach, J . K., Friedlieh, A. L., Myers, G. S., Sanders, C. A., and Scanneil, J . G. : Useful ness and Limitations of Left Heart Catheterization in Mitral Disease, Am. J . Cardiol. 10: 57, 1962. 10. Linder, E., Radner, S., Gustafson, A., Edler, I., and Dahlback, O. : Suprasternal Pressure Curves in Constrietive Pericarditis, Acta med. scandinav. 155: 431, 1956. 11. Marshall, H. W., Woodward, E., Jr., and Wood, E . H . : Hemodynamic Methods for Differentiation of Mitral Stenosis and Régurgitation, Am. J . Cardiol. 2 : 24, 1958. 12. Mclntosh, H. D., Whalen, R. E., Hernandez, R. R., Morris, J . J., and Miller, D. E. : Potential Hazard of Transseptal Left Atrial Catheterization Technique, Am. J . Cardiol. 8: 835, 1961. 13. Morrow, A. G., Braunwald, E., Haller, J . A., and Sharp, E. H. : Left Atrial Pressure Pulse in Mitral Valve Disease, Circulation 16: 399, 1957. 14. Neustadt, J . E., and Shaffer, A. B . : Diagnostic Value of the Left Atrial Pressure Pulse in Mitral Valvular Disease, Am. Heart J . 58: 675, 1959. 15. Musser, B. G., and Goldberg, H. : Left Heart Catheterization. J . THORACIC SURG. 34: 414, 1957. 16. Radner, S. Extended Suprasternal Puncture Technique, Acta med. scandinav. 151: 223, 1955. 17. Radner, S.: Suprasternal Pressure Curves in Mitral Insufficiency, Acta med. scandinav. 152: 1, 1955. 18. Radner, S. : Atrioventricular Activity as Reflected in Suprasternal Pressure Curves, Acta med. scandinav. 164: 1, 1959. 19. Radner, S., Edler, L, and Gustafson, A.: Suprasternal Pressure Curves in Atrial Flutter, Acta med. scandinav. 152: 271, 1955. 20. Radner, S., Erland, L., Dahlback, O., Edler, I., and Gustafson, A.: Suprasternal Pressure Curves in Early Mitral Stenosis, Acta med. scandinav. 154: 299, 1956. 21. Russell, R. O., Carroll, J . F., and Hood, W. G., J r . : Cardiac Tamponade: A Complication of the Technique of Left Heart Catheterization Resulting in a Fatality, Am. J . Cardiol. 13: 558, 1964. 22. Selzer, A., Popper, R. W., Lau, F . Y. K., Morgan, J . J., and Anderson, W. L.: Present Status of Diagnostic Cardiac Catheterization, New England J . Med. 268: 589 and 654, 1963. 23. Susmano, A. and Carleton, R. A.: Transseptal Catheterization of the Left Atrium: Report of an Unusual Complication, New England J . Med. 270: 897, 1964. 24. Willman, V. L., Mudd, J . G., Nigh, C. A., and Hanlon, C. R. : Left Heart Catheterization, Missouri Med. 55: 225, 1958. (For Discussion, see page 979)