Jack J. Curtis

Comparative survival after permanent ventricular and dual chamber pacing for patients with chronic high degree atrioventricular block with and without preexistent congestive heart failure

To determine whether survival after permanent ventricular demand (VVI) pacing differs from survival after permanent dual chamber (DVI or DDD) pacing in patients with chronic high degree atrioventricular (AV) block (Mobitz type II or trifascicular block), 132 patients who received a VVI pacemaker (Group 1) and 48 patients who received a DVI or DDD pacemaker (Group 2) were followed up for 1 to 5 years. There was no significant difference in sex distribution, mean age or incidence of coronary heart disease, hypertension, valvular heart disease, diabetes mellitus, stroke or renal failure between Groups 1 and 2. Overall, the predicted cumulative survival rate at 1, 3 and 5 years was 89, 76 and 73%, respectively, for Group 1 and 95, 82 and 70%, respectively, for Group 2. In patients with preexistent congestive heart failure, the predicted cumulative survival rate at 1, 3 and 5 years was 85, 66 and 47%, respectively, for Group 1 (n = 53) and 94, 81 and 69%, respectively, for Group 2 (n = 20). The 5 year predicted cumulative survival rate was significantly lower in Group 1 patients with preexistent congestive heart failure than in Group 2 patients with the same condition (p less than 0.02). There was no significant difference in 5 year cumulative survival rate between Groups 1 and 2 for patients without preexistent congestive heart failure. The results suggest that permanent dual chamber pacing enhances survival to a greater extent than does permanent ventricular demand pacing in patients with high degree AV block and preexistent congestive heart failure.

Differential gene expression of extracellular matrix components in dilated cardiomyopathy

Extracellular matrix metalloproteinases (MMPs) are activated in dilated cardiomyopathic (DCM) hearts [Tyagi et al. (1996): Mol Cell Biochem 155:13‐21]. To examine whether the MMP activation is occurring at the gene expression level, we performed differential display mRNA analysis on tissue from six dilated cardiomyopathy (DCM) explanted and five normal human hearts. Specifically, we identified three genes to be induced and several other genes to be repressed following DCM. Southern blot analysis of isolated cDNA using a collagenase cDNA probe indicated that one of the genes induced during DCM was interstitial collagenase (MMP‐1). Northern blot analysis using MMP‐1 cDNA probe indicated that MMP‐1 was induced three‐ to fourfold in the DCM heart as compared to normal tissue. To analyze posttranslational expression of MMP and tissue inhibitor of matrix metalloproteinase (TIMP) we performed immunoblot, immunoassay, and substrate zymographic assays. TIMP‐1 and MMP‐1 levels were 37 ± 8 ng/mg and 9 ± 2 ng/mg in normal tissue specimens (P < 0.01) and 2 ± 1 ng/mg and 45 ± 11 ng/mg in DCM tissue (P < 0.01), respectively. Zymographic analysis demonstrated lytic bands at 66 kDa and 54 kDa in DCM tissue as compared to one band at 66 kDa in normal tissue. Incubation of zymographic gel with metal chelator (phenanthroline) abolished both bands suggesting activation of neutral MMP in DCM heart tissue. TIMP‐1 was repressed approximately twentyfold in DCM hearts when compared with normal heart tissue. In situ immunolabeling of MMP‐1 indicated phenotypic differences in the fibroblast cells isolated from the DCM heart as compared to normal heart. These results suggest disruption in the balance of myopathic‐fibroblast cell ECM‐proteinase and antiproteinase in ECM remodeling which is followed by dilated cardiomyopathy.

Heparin-induced thrombocytopenia in open heart surgical patients: Sequelae of late recognition

Most patients undergoing open heart operations have had exposure to heparin for diagnostic and/or therapeutic procedures. Heparin antibody formation and heparin-induced thrombocytopenia with repeat heparin administration can cause high morbidity and mortality from thrombotic complications, especially when delay in diagnosis occurs. From 1981 to 1991, heparin-induced thrombocytopenia was diagnosed in 82 of 4,261 open heart surgical patients (1.9%). Platelet counts less than 100 x 10(9)/L (100,000/microL) or new or recurring thrombotic events prompted suspicion of heparin-induced thrombocytopenia. Heparin-dependent antibody was diagnosed preoperatively in 12 patients (group I) and postoperatively in 70 patients (group II). Heparin was not given postoperatively in group I patients, and complications in this group were limited to bleeding in 3 patients. There were no thromboembolic events and all patients survived. Group II patients had late recognition of heparin-dependent antibody postoperatively, and heparin exposure was continued for varying periods postoperatively. Thirty-seven group II patients (53%) had bleeding complications and 31 (44%) had thromboembolic complications. These complications led to death in 23 group II patients (33%). Heparin-dependent antibody may occur in patients having open heart operations and is a major cause of morbidity and mortality if not diagnosed early with cessation of heparin therapy.

Aneurysms and pseudoaneurysms of the superficial temporal artery caused by trauma

Superficial temporal artery (STA) aneurysms as a result of trauma represent less than 1% of reported aneurysms. During the past 200 years only the type of trauma and the preferred treatment have significantly changed. Patients are generally young men with a recent history of blunt head trauma. They may complain of a mass, headache, or other vague symptoms. Neurologic defects are rare; however, if a neurologic deficit exists, the physician should consider either arteriography or a head CT scan to search for intracranial pathologic conditions. In most cases the diagnosis may be made by obtaining a complete history and physical examination. The treatment of choice is ligation and resection, which may be accomplished with the patient under local or general anesthesia. In rare instances, arteriography with selective embolization may be useful when the traumatic aneurysm is complicated by severe facial trauma. Three cases of STA aneurysms are presented. The history, pathophysiology, origin, presentation, diagnosis, differential diagnosis, and treatment of STA aneurysms are reviewed.

Comparative survival following permanent ventricular and dual-chamber pacing for patients with chronic symptomatic sinus node dysfunction with and without congestive heart failure

To determine whether survival following permanent ventricular demand pacing differs from survival following permanent dual-chamber pacing in patients with symptomatic sinus node dysfunction (unexplained sinus bradycardia, subsidiary rhythms, sinus arrest, sinoatrial block, or the bradycardia/tachycardia syndrome), we followed 79 patients who received a VVI pacemaker (group 1) and 49 patients who received a DVI or DDD pacemaker (group 2) for 1 to 5 years. There was no significant difference in sex distribution, mean age, or the incidence of coronary heart disease, hypertension, valvular heart disease, diabetes mellitus, stroke, or renal failure between groups 1 and 2. Overall, the predicted cumulative survival rates at 1, 3, and 5 years were 89%, 82%, and 74%, respectively, for group 1 and 94%, 86%, and 78%, respectively, for group 2. In patients with preexistent congestive heart failure (CHF), predicted cumulative survival rates at 1, 3, and 5 years were 78%, 69%, and 57%, respectively, for group 1 (n = 23) and 90%, 83%, and 75%, respectively, for group 2 (n = 16). Five-year predicted cumulative survival was significantly lower in group 1 patients with CHF than in group 2 patients with CHF (p less than 0.03). There was no significant difference in 5-year cumulative survival rates between groups 1 and 2 in patients without CHF. The results suggest that permanent dual-chamber pacing enhances survival to a greater extent than permanent ventricular demand pacing in patients with chronic symptomatic sinus node dysfunction and CHF.

Carotid sinus hypersensitivity: Beneficial effects of dual-chamber pacing

Three types of carotid sinus (CS) syndrome have been described: cardioinhibitory, vasodepressor and mixed. For the treatment of symptomatic patients with associated significant cardioinhibition, permanent ventricular demand pacing systems are often implanted. Even with this pacing modality, some patients remain symptomatic because of continued (and at times aggravated) vasodepression. This study assesses the effects of loss of atrial preloading and orthostasis after carotid massage in patients with CS hypersensitivity. Eleven patients were studied using constant intra-arterial pressure measurements during either ventricular (VVI) or atrioventricular sequential (DVI) pacing in both supine or upright positions. The measurements performed included the magnitude of decrease in arterial blood pressure (BP), the rate of decrease of BP and the percent change in BP from baseline values. After carotid massage, all 11 patients had greater hemodynamic change with the VVI than DVI pacing mode, whether in the supine or upright position. The decreases in systolic BP were: DVI (supine) 29 mm Hg, VVI (supine) 48 mm Hg, DVI (upright) 37 mm Hg, and VVI (upright) 59 mm Hg (mean group values, p less than 0.001). The rates of decrease of systolic BP were: DVI (supine) 2.9 mm Hg/s, VVI (supine) 5.7 mm Hg/s, DVI (upright) 4.1 mm Hg/s, and VVI (upright) 8.3 mm Hg/s (mean group values, p less than 0.001). VVI pacing, particularly in the upright position, resulted in a significant increase in the incidence of patient symptoms (p = 0.03). Thus, in CS hypersensitivity, VVI pacing results in significant hemodynamic deterioration compared to DVI mode. This aggravation of the vasodepressor component results in increased patient symptoms, and therefore, DVI is the optimal pacing mode.

Elevated hemidiaphragm after cardiac operations: Incidence, prognosis, and relationship to the use of topical ice slush

We have reviewed chest roentgenograms of 745 patients before hospital dismissal after cardiac operations and serially to determine the incidence and prognosis of elevated hemidiaphragm and any relationship to the use of topical ice slush (TIS) in myocardial preservation. All patients had similar myocardial preservation techniques including moderate systemic hypothermia and 4 degrees C saline solution poured over the heart at aortic clamping. During a 12-month period, TIS was added to the saline bath. Two (2.4%) of 84 patients before TIS and 5 (2.5%) of 201 consecutive patients operated on since discontinuing TIS had elevated hemidiaphragm on the predismissal roentgenogram. Of 460 patients in whom TIS was employed, 109 (23.7%) had elevated hemidiaphragm (p less than 0.001). When TIS was employed, elevated hemidiaphragm developed in 72 (26%) of 280 patients without internal mammary artery takedown versus 13 of 33 patients (39.4%) with takedown of the internal mammary artery (p = 0.047). Ninety-nine patients with elevated hemidiaphragm were available for follow-up at 1 month, at which time 79 (79.8%) continued to have elevated diaphragm. At 1 year, 14 (21.9%) of 64 patients had persistent diaphragm elevation. We conclude that TIS predisposes to elevated diaphragm and that the incidence is increased when the internal mammary artery is harvested.

Coronary revascularization in the elderly: Determinants of operative mortality

Over a 13-year period, 668 patients 70 years of age or older underwent isolated primary coronary artery bypass grafting at our institution. There were 472 men and 196 women, ranging from 70 to 90 years of age (median age, 74 years). Hospital mortality was 5.2% (35/668). In patients 70 to 79 years of age, hospital mortality was 4.2% (25/600), whereas in patients 80 years of age or older, mortality was 14.7% (10/68; p < 0.001). Twenty-seven clinical or hemodynamic variables hypothesized as predictors of operative mortality were examined. Mortality was higher in women than in men (9% versus 3.6%; p = 0.006). Those who died were a mean of 3 years older (77 versus 74 years old; p < 0.05) and were more likely to have unstable angina or Canadian class III or IV angina (p < 0.01). Patients requiring urgent operations, preoperative intraaortic balloon assist, intravenous nitroglycerin, or inotropic agents, and those with preoperative hypotension or cardiac arrest were most likely to die in the hospital (p < 0.001). Multivariate logistic regression analysis revealed advancing age, female sex, bypass time, urgency of operation, preoperative cardiac arrest, and unstable angina as primary determinants of mortality (p < 0.05). Although mortality after coronary artery bypass grafting increases with age, the greatest risk of death is in the acutely ill patient with few options for management other than surgical intervention.

Clinical spectrum of paraesophageal herniation

Paraesophageal herniation is a potentially devastating condition of the gastroesophageal hiatus commonly manifesting in patients of advanced age with other significant medical problems. Surgical treatment is generally indicated to avoid catastrophe related to gastric volvulus. The operative approach utilized should be individualized to the patients pathophysiologic condition rather than attempting to apply a single repair for all patients with this heterogeneous clinical problem.

Incidence and predictors of supraventricular dysrhythmias after pulmonary resection.

BACKGROUND Patients undergoing pulmonary resection were evaluated prospectively in an effort to determine the incidence of and predictors for the development of postoperative supraventricular dysrhythmias. Specifically, we wished to test the hypothesis that the incidence of postoperative supraventricular dysrhythmias is dependent on the magnitude of pulmonary resection. METHODS One hundred sixteen patients undergoing pulmonary resection had continuous Holter monitoring preoperatively, the day of operation, and the second postoperative day, as well as continuous cardiac monitoring throughout hospitalization. Holter interpretation was blinded to extent of resection. RESULTS Twenty-six patients underwent pneumonectomy, 7 bilobectomy, 47 lobectomy, and 36 wedge resection. Twenty-six patients (22.4%) had supraventricular dysrhythmias, all atrial fibrillation +/- flutter. The incidence of atrial fibrillation with pneumonectomy, bilobectomy, single lobectomy, and wedge resection was 46.1%, 14.3%, 17.0%, and 13.8%, respectively (p < 0.005 pneumonectomy versus others). Overall, 31% of patients having pneumonectomy required pharmacologic therapy for dysrhythmia compared with 16% of patients having lesser resections, (p = 0.03). The peak incidence of onset of atrial fibrillation occurred on postoperative days 2 and 3 and lasted for less than 1 to 7 days, average 2.5 days. The average age of patients with dysrhythmias (64 years) was greater than those without (58 years) (p = 0.039). Thirty pre- and postoperative variables tested were not found to be significant predictors for development of postoperative atrial fibrillation. CONCLUSIONS Atrial fibrillation occurs commonly after pulmonary resections but is not predictable. Development of atrial fibrillation is not dependent on the magnitude of pulmonary resection but is associated with the procedure pneumonectomy for reasons not elucidated.