LETTERS
I was fortunate to work with all these gentlemen at the time, but I do not feel entitled to receive credit for external pacing. Peter P. Tarjan, PhD Cordis Corporation Miami, Florida Reference 1. Parsonnet
V: Permanent pacing of the heart. Am J Cardiol39:250-256,
References 1. Raizas 0, Wagner OS, Hackel DB: lnstantanews nonarrhythmic cardiac death in acute myocardial infarction. Am J Cardiol39:1-6. 1977 2. Morton DE, Gardner IW, MoKlnnong E: Electrocardiogram in ventricular rupture after myocardial infarction. Am Heart J 72:617-621, 1966 3. Mours AAH, Vos AK. Verhey JB, et al: Electrocardiogram during cardiac rupture by myocardial infarction. Br Heart J 32:232-235. 1970 4. Cord&o A. Ravara LP. Ahnelda MO. at al: Les dilatirations myocardiauas mortellas au tours da I’infarctus aigu. Arch Mai Coaur 66:1003-1008. 1673 5. PenMer P, Hemon P, Btanc JJ, et al: Les ruptwes du cow B la phase aigua de I’infarctus d” Myocarde. Arch Mal Cceur 66:711-716. 1975
1977
REPLY HISTORY OF CARDIAC
PACING-II
William Chardack has written me concerning a few erroneous references in my review of permanent pacing: In 1959 Hunter and his colleagues1 did implant the first myocardial electrode, not the first pacemaker. Chardack et a1.2 reported the first pacemaker implantation in 1959. The first engineering work on pacemakers by Greatbatch was actually done in 1958, not in 1959 as indicated in Table III. Victor Parsonnet, MD, FACC Department of Surgery Newark Beth Israel Medical Center Newark, New Jersey References 1. Hunter SW, Roth NA, BernardaD. el al:A bipolar mywardial electrode for complete heart block. J Lancet 79:506-506. 1959 2. Char&ok WM, Gage AA, Greatbatch W: A transistwizad. s%lf-containsd. implantable pacemaker for the long term correction of complete heart block. Surgery 46~643. 1960 3. GNawal& w, Charda& WM: A transistwizad implantable pacemaker for the -term correction of complete atrioventricular block. Med Electron NEREM 46:643, 1959
MYOCARDIAL
The anatomic observation of myocardial rupture in all 19 cases in Dr. Cordeiro’s series is indeed remarkable. We had expected to find rupture in our patients and were surprised when it was not present. We suspect that it was only by chance that no cases of rupture were included in the seven that were studied. It would be important to know the specific findings that were termed “rupture” in Cordeiro’s series. Was percardial tamponade found in all patients? If not, was rupture really the cause of death in these patients? Could the evidence of a rupture have been produced post mortem during attempts at resuscitation? The term “electrohemodynamic dissociation” would indeed be preferable to “electromechanical dissociation” because the generation of some cardiac pumping capability has been demonstrated in some of these instances.’ It would be important to obtain full 12 lead electrocardiograms at the time of occurrence of this phenomenon. This might provide insight concerning etiology. Galen S. Wagner, MD Donald B. Hackel, MD Department of Medicine Cardiovascular Division Duke University Medical Center Durham, North Carolina
RUPTURE
Raizes et al.,’ writing of “instantaneous nonarrhythmic death” in acute myocardial infarction, use this designation for the sudden cessation of all signs of mechanical activity of the heart although sinus rhythm, as assessed with the electrocardiogram, was maintained for some time. This syndrome, generally named electromechanical dissociation (although we consider electrohemodynamic dissociation a more proper term), is usually ascribed to a cardiac rupture.2-5 It is surprising that none of the seven patients meeting this criteria at autopsy had cardiac rupture. In addition, the authors state that the three cases of rupture recorded in 10 years did not meet the criteria for this syndrome. Our personal data are just in opposition to these findings. In an 8 year experience in our coronary care unit, we followed up 2,032 casts of acute transmural infarction in which the total mortality rate was 14 percent. We recorded 31 cases of death in patients with electrohemodynamic dissociation, with 19 necropsy examinations. In all cases the heart manifested rupture of the free wall of the ventricle that occurred in the first 3 days of infarction in all but three cases. All patients were in classes I and II of the Killip classification, and most were more than 60 years old and female. In light of these two separate groups of patients, we wonder if a more detailed analysis of the terminal electrocardiogram would help to differentiate these mechanisms of death. Arsenio Cordeiro, MD, FACC Unidade de Tratamento lntensivo de Coronaries University Hospital (Hospital de Santa Maria) Lisbon, Portugal
Reference 1. CauMaki JG, Z& L, Harlfwme JW: Blood calcium levels in ths presence of artariographic contrast material. Circulation 52:119-123. 1974
COMMENT
I am glad to provide further information about our 19 cases of cardiac rupture. In our experience rupture of the free wall results from an intramural dissection, usually a sinuous, multichannel hematoma, beginning with an endocardial tear and ending in single or multiple lacerated openings in the epicardium. There was a large amount of blood and clotting in the pericardial cavity in all cases. Cardiac massage was not attempted in any case. In three cases we tried unsuccessfully to decompress the tamponade by pericardiocentesis. Reference 4 describes our early cases. Succeeding cases confirmed these observations. Arsenio Cordeiro, MD, FACC
ECHOCARDIOGRAM
IN MITRAL STENOSIS
Parisi et al.’ state that there have been no published prospective series evaluating the accuracy of M mode scans in grading the severity of mitral stenosis. I therefore draw the authors’ attention to a prospective study2 in 26 patients evaluating the accuracy of conventional echocardiography in predicting the degree of mitral stenosis and pliability of valve
March 1979
The American Journal of CARDfOLOGY
Volume 41
615
LETTERS
References 1. Paris1 AF, TOW GE, Sasahara AI: Clinical appraisal of current nuclear and other noninvasive cardiac diagnostic techniques. Am J Cardiol 36: 722-730. 1976 2. liOrga JH, Kq VE, Holland WE, et al: Conelation of diagnostic echographic featwes of mitral stenosis with findings at calheterizatial and svgery In. Uftrasound in Medicine. Vol 2 (White D. Barnes F. ed). New York, Plenum Publishing. 1976. p 71
REPLY
FIGURE 1. Two dimensional cross-sectional and M mode views of a Stenotic mitral valve. A and C, diastolic cross-sectional views of the mitral orifice ma& with a phased array sects scanner. The radii (white lines) indicate the direction of a single beam for the M mode display. In C the radius is near the commissure rather than at the center of the slenotic wifice. Et. M mode record made along the beam directed Uvwgh the center of the mitral wifice as indicated in A; D, M mode accord from the radius shown in C. The E-F slope and valve excursion are less in D than in B.
leaflets when compared with cardiac catheterization data and measurements made at open commissurotomy. Echocardiographic categorization of mitral stenosis as severe (E-F slope 15 mm/set), moderate (15 to 25 mm/set) or mild (25 to 35 mm/set) was compared with estimates of the mitral valve area as calculated with the Gorlin formula and measured with calibrated probes at surgery: (severe CO.5 cm2, moderate 0.5 to 1.00 cm2 and mild 1.00 to 1.5 cm2). In 15 patients there was agreement between the echocardiographic and surgical estimate of the severity of mitral stenosis; in the remaining 11 patients the echocardiogram indicated greater stenosis than was found at surgery. Among the 21 patients whose valve area was calculated with the Gorlin formula, there was agreement in 6 between the echocardiographic and the Gorlin estimates of the severity of mitral stenosis; in 13 the echocardiogram indicated greater stenosis than the Gorlin formula, and in 2 the reverse was true. In the latter two patients the echocardiographic and surgical assessments of the severity of stenosis were in agreement. The presence of a low cardiac index, atria1 fibrillation and mitral regurgitation did not significantly contribute to these relations. Surgical assessment of impaired pliability was related to anterior mitral leaflet excursion of less than 20 mm and less than 15 mm. Ten of 14 patients considered to have impaired pliability at surgery had anterior leaflet excursions of less than 20 mm. One with pliable leaflets had an anterior leaflet excursion of less than 20 mm (P
I was fortunate to work with all these gentlemen at the time, but I do not feel entitled to receive credit for external pacing. Peter P. Tarjan, PhD Cordis Corporation Miami, Florida Reference 1. Parsonnet
V: Permanent pacing of the heart. Am J Cardiol39:250-256,
References 1. Raizas 0, Wagner OS, Hackel DB: lnstantanews nonarrhythmic cardiac death in acute myocardial infarction. Am J Cardiol39:1-6. 1977 2. Morton DE, Gardner IW, MoKlnnong E: Electrocardiogram in ventricular rupture after myocardial infarction. Am Heart J 72:617-621, 1966 3. Mours AAH, Vos AK. Verhey JB, et al: Electrocardiogram during cardiac rupture by myocardial infarction. Br Heart J 32:232-235. 1970 4. Cord&o A. Ravara LP. Ahnelda MO. at al: Les dilatirations myocardiauas mortellas au tours da I’infarctus aigu. Arch Mai Coaur 66:1003-1008. 1673 5. PenMer P, Hemon P, Btanc JJ, et al: Les ruptwes du cow B la phase aigua de I’infarctus d” Myocarde. Arch Mal Cceur 66:711-716. 1975
1977
REPLY HISTORY OF CARDIAC
PACING-II
William Chardack has written me concerning a few erroneous references in my review of permanent pacing: In 1959 Hunter and his colleagues1 did implant the first myocardial electrode, not the first pacemaker. Chardack et a1.2 reported the first pacemaker implantation in 1959. The first engineering work on pacemakers by Greatbatch was actually done in 1958, not in 1959 as indicated in Table III. Victor Parsonnet, MD, FACC Department of Surgery Newark Beth Israel Medical Center Newark, New Jersey References 1. Hunter SW, Roth NA, BernardaD. el al:A bipolar mywardial electrode for complete heart block. J Lancet 79:506-506. 1959 2. Char&ok WM, Gage AA, Greatbatch W: A transistwizad. s%lf-containsd. implantable pacemaker for the long term correction of complete heart block. Surgery 46~643. 1960 3. GNawal& w, Charda& WM: A transistwizad implantable pacemaker for the -term correction of complete atrioventricular block. Med Electron NEREM 46:643, 1959
MYOCARDIAL
The anatomic observation of myocardial rupture in all 19 cases in Dr. Cordeiro’s series is indeed remarkable. We had expected to find rupture in our patients and were surprised when it was not present. We suspect that it was only by chance that no cases of rupture were included in the seven that were studied. It would be important to know the specific findings that were termed “rupture” in Cordeiro’s series. Was percardial tamponade found in all patients? If not, was rupture really the cause of death in these patients? Could the evidence of a rupture have been produced post mortem during attempts at resuscitation? The term “electrohemodynamic dissociation” would indeed be preferable to “electromechanical dissociation” because the generation of some cardiac pumping capability has been demonstrated in some of these instances.’ It would be important to obtain full 12 lead electrocardiograms at the time of occurrence of this phenomenon. This might provide insight concerning etiology. Galen S. Wagner, MD Donald B. Hackel, MD Department of Medicine Cardiovascular Division Duke University Medical Center Durham, North Carolina
RUPTURE
Raizes et al.,’ writing of “instantaneous nonarrhythmic death” in acute myocardial infarction, use this designation for the sudden cessation of all signs of mechanical activity of the heart although sinus rhythm, as assessed with the electrocardiogram, was maintained for some time. This syndrome, generally named electromechanical dissociation (although we consider electrohemodynamic dissociation a more proper term), is usually ascribed to a cardiac rupture.2-5 It is surprising that none of the seven patients meeting this criteria at autopsy had cardiac rupture. In addition, the authors state that the three cases of rupture recorded in 10 years did not meet the criteria for this syndrome. Our personal data are just in opposition to these findings. In an 8 year experience in our coronary care unit, we followed up 2,032 casts of acute transmural infarction in which the total mortality rate was 14 percent. We recorded 31 cases of death in patients with electrohemodynamic dissociation, with 19 necropsy examinations. In all cases the heart manifested rupture of the free wall of the ventricle that occurred in the first 3 days of infarction in all but three cases. All patients were in classes I and II of the Killip classification, and most were more than 60 years old and female. In light of these two separate groups of patients, we wonder if a more detailed analysis of the terminal electrocardiogram would help to differentiate these mechanisms of death. Arsenio Cordeiro, MD, FACC Unidade de Tratamento lntensivo de Coronaries University Hospital (Hospital de Santa Maria) Lisbon, Portugal
Reference 1. CauMaki JG, Z& L, Harlfwme JW: Blood calcium levels in ths presence of artariographic contrast material. Circulation 52:119-123. 1974
COMMENT
I am glad to provide further information about our 19 cases of cardiac rupture. In our experience rupture of the free wall results from an intramural dissection, usually a sinuous, multichannel hematoma, beginning with an endocardial tear and ending in single or multiple lacerated openings in the epicardium. There was a large amount of blood and clotting in the pericardial cavity in all cases. Cardiac massage was not attempted in any case. In three cases we tried unsuccessfully to decompress the tamponade by pericardiocentesis. Reference 4 describes our early cases. Succeeding cases confirmed these observations. Arsenio Cordeiro, MD, FACC
ECHOCARDIOGRAM
IN MITRAL STENOSIS
Parisi et al.’ state that there have been no published prospective series evaluating the accuracy of M mode scans in grading the severity of mitral stenosis. I therefore draw the authors’ attention to a prospective study2 in 26 patients evaluating the accuracy of conventional echocardiography in predicting the degree of mitral stenosis and pliability of valve
March 1979
The American Journal of CARDfOLOGY
Volume 41
615
LETTERS
References 1. Paris1 AF, TOW GE, Sasahara AI: Clinical appraisal of current nuclear and other noninvasive cardiac diagnostic techniques. Am J Cardiol 36: 722-730. 1976 2. liOrga JH, Kq VE, Holland WE, et al: Conelation of diagnostic echographic featwes of mitral stenosis with findings at calheterizatial and svgery In. Uftrasound in Medicine. Vol 2 (White D. Barnes F. ed). New York, Plenum Publishing. 1976. p 71
REPLY
FIGURE 1. Two dimensional cross-sectional and M mode views of a Stenotic mitral valve. A and C, diastolic cross-sectional views of the mitral orifice ma& with a phased array sects scanner. The radii (white lines) indicate the direction of a single beam for the M mode display. In C the radius is near the commissure rather than at the center of the slenotic wifice. Et. M mode record made along the beam directed Uvwgh the center of the mitral wifice as indicated in A; D, M mode accord from the radius shown in C. The E-F slope and valve excursion are less in D than in B.
leaflets when compared with cardiac catheterization data and measurements made at open commissurotomy. Echocardiographic categorization of mitral stenosis as severe (E-F slope 15 mm/set), moderate (15 to 25 mm/set) or mild (25 to 35 mm/set) was compared with estimates of the mitral valve area as calculated with the Gorlin formula and measured with calibrated probes at surgery: (severe CO.5 cm2, moderate 0.5 to 1.00 cm2 and mild 1.00 to 1.5 cm2). In 15 patients there was agreement between the echocardiographic and surgical estimate of the severity of mitral stenosis; in the remaining 11 patients the echocardiogram indicated greater stenosis than was found at surgery. Among the 21 patients whose valve area was calculated with the Gorlin formula, there was agreement in 6 between the echocardiographic and the Gorlin estimates of the severity of mitral stenosis; in 13 the echocardiogram indicated greater stenosis than the Gorlin formula, and in 2 the reverse was true. In the latter two patients the echocardiographic and surgical assessments of the severity of stenosis were in agreement. The presence of a low cardiac index, atria1 fibrillation and mitral regurgitation did not significantly contribute to these relations. Surgical assessment of impaired pliability was related to anterior mitral leaflet excursion of less than 20 mm and less than 15 mm. Ten of 14 patients considered to have impaired pliability at surgery had anterior leaflet excursions of less than 20 mm. One with pliable leaflets had an anterior leaflet excursion of less than 20 mm (P
