Search PubMed⌕ Search

Biomedical subjects

V Parsonnet

Publications and source records attributed to V Parsonnet.

At least 181 records · Page 10Linked to original sources

Delayed sternal closure following open-heart operation.

Between June, 1976, and December, 1980, 29 patients underwent delayed sternal closure at the Newark Beth Israel Medical Center. The indications were enlarged heart with tamponade when the mediastinum was closed, poor lung compliance, hemodynamic instability due to intractable arrhythmias or coagulopathy, and presence of a mediastinal assist device. Following an open-heart procedure, the retrosternal space may no longer accommodate the heart and approximation of the sternum will produce hypotension and elevation of right and left end-diastolic pressures. In such instances, only the skin is closed and between one to four days later, the wound is closed in a routine manner. There are several advantages of the procedure: hemodynamic stability; quick access to the heart for massage or evacuation of clots; and possibility of removing an intraaortic balloon in the ascending aorta without leaving a large Dacron tube. Of the 29 patients treated, 19 were long-term survivors and only 1 patient had a minor superficial wound infection. Although it is not recommended that this procedure be utilized routinely or indiscriminately, its judicious use will add flexibility in the management of selected and difficult cases.

Adult↗

Corrosion of pacemaker electrodes.

As improvements in pacemaker components and design increase pacemaker life, problems with other components may emerge such as corrosion of the electrodes. Explanted electrodes were examined under a scanning electron microscope and the degree of corrosion was graded and correlated with the reasons for explantation, the status of the explanted pacemaker, and the duration of the implant. Fifty-six explanted electrodes were removed for loss of capture or sensing, pacemaker extrusion, broken wires, or after death. A numerical grading system was used to qualitate the degree of corrosion. The pacemaker itself was retrieved in 50 cases, permitting evaluation of the entire pacing system. The dc component of the pacemaker output was measured. Without the aid of magnification most electrodes appeared shiny and smooth. With one exception all corrosion was microscopic. Significant corrosion was seen on all pacemaker electrodes that had been connected to pacemakers with dc offset currents greater than 5 microamperes. All except the "youngest" explanted electrode showed some degree of corrosion. The data suggest that corrosion was directly related to the duration of implantation. With the possible exception of one case, no consistent adverse clinical effects were observed, even when electrodes were heavily corroded. Whether or not corrosion eventually will progress to the point that clinical problems become manifest cannot be predicted at this time.

Arrhythmias, Cardiac↗

A revised code for pacemaker identification. Pacemaker Study Group.

The three-position ICHD code designating pacemaker function has been widely adopted. A revision, expanding the code from three to five positions, incorporates the first three positions as in the earlier version, but includes position IV, programmable functions, and position V, tachyarrhythmia functions. The code indicates how the pacemaker is employed, not necessarily the purpose for which it was designed. For example, a single-chamber inhibited pulse generator with multiprogrammable capabilities which interrupts a tachycardia by a burst of rapid pacing is designated as VVI,MB if placed in the ventricle, and AAI,MB if in the atrium.

Arrhythmias, Cardiac↗

Infected aneurysms of the abdominal aorta.

Infected aneurysms of the abdominal aorta are relatively uncommon, but potentially lethal if improperly managed. Two case reports emphasize the importance of the preoperative aortogram for accurate diagnosis. We stress the principles of total excision of infected tissue and revascularization in uninfected tissue planes. A useful vascular reconstructive technique consisting of unilateral axillofemoral bypass and an ilioiliac anastomosis was used in both patients.

Aged↗

A 12-year experience with femorofemoral crossover grafts.

One hundred thirty-three patients with unilateral iliac artery obstruction were treated with crossover femorofemoral grafts and followed up for one to 12 years. Cumulative patency was 73.3% at five years and 63.6% at ten years. There were 17 early closures with ten unsuccessful revisions and 22 late failures between three and 122 months. Inability to establish adequate runoff was the primary cause of early failure, and the progression of distal disease was the major cause of late failures. In only five cases did progressive disease of the donor artery cause failure of the graft. Operative morbidity and mortality were low (6%), and the results compare favorably with alternative methods of treating unilateral iliac artery occlusions.

Adult↗

Clinically recognized limb ischemia in the neonate after umbilical artery catheterization.

During a 4 year period, 1,461 critically ill neonates were admitted to the newborn intensive care unit of the Newark Beth Israel Medical Center, and 507 (35 percent) had umbilical artery catheters inserted for physiologic monitoring. In five patients (1 percent) clinically significant limb ischemia developed as a result of catheter complications. Frank gangrene was observed in three patients; two died from the primary illness soon after the onset of gangrene and the third survived after leg amputation. The other two infants had advanced ischemia that responded favorably to catheter removal and heparinization. Irreversible limb ischemia in this setting is infrequent, and milder forms are usually unrecognized or undocumented. High placement of the catheter or the length of time it is in place were not related to complications. Limb ischemia occurred soon after catheter insertion rather than after its protracted use. Major complications may be reduced by placement of the catheter in the lower abdominal aorta or internal iliac artery, clinical awareness and observation and frequent noninvasive monitoring. Immediate catheter removal and intravenous anticoagulation are warranted if ischemia persists. From this study, we believe that the benefits derived from judicious umbilical artery catheterization outweigh any inherent risk.

Catheterization↗

Characteristics of intracardiac electrograms II: Atrial endocardial electrograms.

The intra-atrial electrograms (P-wave and QRS complex) of newly implanted electrodes were recorded, and the time and frequency domain characteristics compared. The sensing impedance properties of the atrial electrode were studied in relation to the characteristics of both atrial and ventricular electrograms, and specific differences between the P and R-waves were identified. These values, particularly the amplitude and frequency components, were sufficiently distinct to make differentiation by pacemaker sensing circuits selective and reliable.

Cardiac Pacing, Artificial↗

An experimental method for thermal control of heart rate: work in progress.

Evaluation of the postoperative course of coronary artery bypass patients shows that a number develop supraventricular arrhythmias that may be responsive to sino-atrial node (SAN) cooling. The sinus rate can be controlled within a clinically useful range with topical cooling probes (thermodes). The data on the variations of heart rate caused by modest nodal hypothermia indicate that a nonpharmacologic clinical system for control of supraventricular tachyarrhythmias is feasible. Prototype thermodes suitable for SAN implantation have been developed.

Animals↗

Limb ischemia during intra-aortic balloon pumping: indication for femorofemoral crossover graft.

Catheter insertion for intra-aortic balloon pumping (IABP) was successful in 91% of 332 candidates. Fifty-three patients (16.5%) had significant catheter-associated vascular complications, of which lower extremity ischemia with threatened limb loss was the most prevalent (70%). Thirty-six of these patients required an angioplastic repair or vascular grafting. Of the 36, 19 patients with ischemia who needed continued balloon support received femorofemoral (F-F) grafts to restore and maintain adequate limb perfusion. Wound infection occurred in six of the patients but there was no limb loss. F-F grafting is a simple procedure that requires little time and allows one to maintain IABP for prolonged periods without concern for critical obstruction to limb perfusion.

Adult↗