Permanent Pacing of the Heart: A Comment on Technique VICTOR PARSONNET, MD, FACC Alewar&, New Jersey
Fixation of electrodes directly into the myocardium, the original technique for pacemaker implantation, almost disappeared from the scene for 10 years. Less than 5 percent of “pacemaker doctors” persisted in transthoracic implantation. As one might suspect, the physicians who persisted were thoracic surgeons; they argued for their method on the basis of its simplicity and swiftness and the long-term security of electrode position. Most other physicians, about one third of whom were cardiologists or internists, and two thirds surgeons, had switched to transvenous pacing because this method could be performed in patients of any age, under local anesthesia, with low operative morbidity and mortality. Recently an interest in direct myocardial implantation was rekindled by the development of the sutureless or so-called “screw-in” electrode, and by the disclosure by some physicians that in their hands transvenous pacing was associated with a frightfully high incidence of early electrode malposition-as high as 59 percent in one report! (For the sake of brevity, malposition here includes dislodgment and ventricular perforation.) Because proponents of each technique are now figuratiyely toe to toe, it behooves us to evaluate the relevant arguments. “Swiftness” and “simplicity” are characteristics that may be attributed to both methods but, one asks, swift and simple for whom? Surely transthoracic pacing would be neither swift nor simple for an internist, nor would transvenous pacing be simple or swift for every surgeon. A cardiologist, actually, could not perform a transthoracic operation, because no hospital would give him operative privileges. And yet, paradoxically, surgeons h&e slipped into the catheterization laboratory (because a small incision was needed?) and have been inserting transvenous pacemakers. In fact, transvenous pacing is so “simple” that many centers have given this operative responsibility to junior physicians, and sometimes to house officers. The real issue is the problem of electrode dislodgment. Were electrodes as securely positioned with transvenous pacing as they are with transthoracic pacing, there would be no valid argument for pericarFrorh the Department of Surgery, Newaik Beth Israel Medical Center, Newark, N. J. Address for reprints: Victor Parsonnet, MD, Department of Surgery, Newark Beth Israel Medical Center, 201 Lyons Ave., Newark, N. J. 07112.
268
August 1975
The American Journal of CAqDlOLOGY
diotomy, however small the opening. Even though transthoracic pacing can be done with little morbidity and mortality, general endotracheal anesthesia is usually used (although epigastric incisions and transthoracic operations may be done under local anesthesia), the pericardium must be opened and the heart must be exposed. There are, of course, those who argue differently, but surely these factors will increase morbidity and mortality. Add to that the problem of infection, should it occur: Removal of wires by the transvenous route is a far less serious consequence than another thoracotomy. Other complications that are peculiar to transvenous pacing, such as damage to the tricuspid valve, air embolization and late perforations are not being ignored in this editorial, but they are relatively rare, and for the sake of this analysis are more than balanced by other complications that are peculiar to transthoracic pacing. In the Inter-Society Commission for Heart Disease Resources report on pacemakers,’ the issue of an acceptable incidence of transvenous electrode malposition was discussed. It was suggested that a figure of early dislodgment high& than 5 percent calls for a review of results by a proper audit committee (now probably PSRO), and for modification of physicians’ privileges. Our own figures for 1973 and 1974 show 9 dislodgments in 219 primary ventricular transvenous insertions (4.1 percent). A second repositioning of the 9 was never required. Perhaps this indicates that the operation could have been done better the first time! Permanent transthoracic pacing is never used at our institution except as an incidental procedure when the heart is exposed for another reason, or in rare problem situations. Since 1964 we have used the transthoracic approach five times in 1,030 complete pacemaker insertions. Transvenous pacing can be done with only a trivial incidence of complications; it is the safest and simplest technique available. In our opinion it is the preferred pacing method in almost all situ&ions, provided the operation is performed by a skilled physician who is specifically trained in the technique and all its ramifications. Reference 1. Parsonnet V, Furman S, Smyth NPD: Implantable cardiac pace-
Volume 36
makers. Status reports and resource guideline. ICHD Report. Circulation 50: A-21-A-35, 1974
Fixation of electrodes directly into the myocardium, the original technique for pacemaker implantation, almost disappeared from the scene for 10 years. Less than 5 percent of “pacemaker doctors” persisted in transthoracic implantation. As one might suspect, the physicians who persisted were thoracic surgeons; they argued for their method on the basis of its simplicity and swiftness and the long-term security of electrode position. Most other physicians, about one third of whom were cardiologists or internists, and two thirds surgeons, had switched to transvenous pacing because this method could be performed in patients of any age, under local anesthesia, with low operative morbidity and mortality. Recently an interest in direct myocardial implantation was rekindled by the development of the sutureless or so-called “screw-in” electrode, and by the disclosure by some physicians that in their hands transvenous pacing was associated with a frightfully high incidence of early electrode malposition-as high as 59 percent in one report! (For the sake of brevity, malposition here includes dislodgment and ventricular perforation.) Because proponents of each technique are now figuratiyely toe to toe, it behooves us to evaluate the relevant arguments. “Swiftness” and “simplicity” are characteristics that may be attributed to both methods but, one asks, swift and simple for whom? Surely transthoracic pacing would be neither swift nor simple for an internist, nor would transvenous pacing be simple or swift for every surgeon. A cardiologist, actually, could not perform a transthoracic operation, because no hospital would give him operative privileges. And yet, paradoxically, surgeons h&e slipped into the catheterization laboratory (because a small incision was needed?) and have been inserting transvenous pacemakers. In fact, transvenous pacing is so “simple” that many centers have given this operative responsibility to junior physicians, and sometimes to house officers. The real issue is the problem of electrode dislodgment. Were electrodes as securely positioned with transvenous pacing as they are with transthoracic pacing, there would be no valid argument for pericarFrorh the Department of Surgery, Newaik Beth Israel Medical Center, Newark, N. J. Address for reprints: Victor Parsonnet, MD, Department of Surgery, Newark Beth Israel Medical Center, 201 Lyons Ave., Newark, N. J. 07112.
268
August 1975
The American Journal of CAqDlOLOGY
diotomy, however small the opening. Even though transthoracic pacing can be done with little morbidity and mortality, general endotracheal anesthesia is usually used (although epigastric incisions and transthoracic operations may be done under local anesthesia), the pericardium must be opened and the heart must be exposed. There are, of course, those who argue differently, but surely these factors will increase morbidity and mortality. Add to that the problem of infection, should it occur: Removal of wires by the transvenous route is a far less serious consequence than another thoracotomy. Other complications that are peculiar to transvenous pacing, such as damage to the tricuspid valve, air embolization and late perforations are not being ignored in this editorial, but they are relatively rare, and for the sake of this analysis are more than balanced by other complications that are peculiar to transthoracic pacing. In the Inter-Society Commission for Heart Disease Resources report on pacemakers,’ the issue of an acceptable incidence of transvenous electrode malposition was discussed. It was suggested that a figure of early dislodgment high& than 5 percent calls for a review of results by a proper audit committee (now probably PSRO), and for modification of physicians’ privileges. Our own figures for 1973 and 1974 show 9 dislodgments in 219 primary ventricular transvenous insertions (4.1 percent). A second repositioning of the 9 was never required. Perhaps this indicates that the operation could have been done better the first time! Permanent transthoracic pacing is never used at our institution except as an incidental procedure when the heart is exposed for another reason, or in rare problem situations. Since 1964 we have used the transthoracic approach five times in 1,030 complete pacemaker insertions. Transvenous pacing can be done with only a trivial incidence of complications; it is the safest and simplest technique available. In our opinion it is the preferred pacing method in almost all situ&ions, provided the operation is performed by a skilled physician who is specifically trained in the technique and all its ramifications. Reference 1. Parsonnet V, Furman S, Smyth NPD: Implantable cardiac pace-
Volume 36
makers. Status reports and resource guideline. ICHD Report. Circulation 50: A-21-A-35, 1974
