James W. Kilman

Occult constrictive pericardial disease. Diagnosis by rapid volume expansion and correction by pericardiectomy.

Significant pericardial disease can exist without overt manifestations. Occult constrictive pericardial disease (OCPD) is identified by normal baseline hemodynamics and normal left ventricular systolic function with a characteristic response to rapid volume infusion. Following the intravenous administration of 1000 ml of normal saline over six to eight minutes, striking elevations of filling pressures are seen; however, diagnosis depends specifically upon a) the development of typical pressure pulse morphology of constriction, b) loss or reversal of respiratory variation of right atrial pressure, and c) precise diastolic equilibration of intracardiac pressures. Nineteen patients with OCPD have been identified in a five year period. Unexplained fatigue, dyspnea and chest pain was the uniform pattern of presentation. Eleven have undergone pericardiectomy resulting in a dramatic symptomatic improvement in all. Each demonstrated gross and/or microscopic evidence of pericardial disease. Recatheterization with volume infusion in five patients following pericardiectomy has revealed return to normal or near normal hemodynamics. This study describes the method for diagnosis of OCPD and recommends pericardiectomy for the management of disabling symptoms.

Late failure in vein grafts: mediating factors in subendothelial fibromuscular hyperplasia.

Late failure of autologous vein grafts often results from excessive subendothelial fibromuscular hyperplasia. Varying factors have been implicated in this process, but the exact etiology remains unclear. In this study, three groups of animals were studied which had sections of common carotid artery replaced with autologous vein grafts. Group I had simple replacement, while Groups II and III had grafts supported by either tightly woven or loose mesh dacron prostheses. Thrombosis occurred only in the unsupported grafts. Unsupported grafts also had more subendothelial proliferation when compared to the loose mesh group. The combined thickness of the intima-media correlated inversely with the number of vasa present within the vein graft wall, i.e. significantly more vascularization was found in the mesh supported group when compared to the other groups. Grafts supported with the tightly woven prosthesis were relatively impervious to the ingrowth of vasa vasora. The data suggest that persistent distension of the graft wall by intra-arterial pressure influences the degree of subendothelial fibromuscular hyperplasia and may be interrelated to revascularization of the graft wall per se.

Myxomatous mitral valves: collagen dissolution as the primary defect.

We studied the morphologic and histologic characteristics of redundant prolapsing (“myxomatous”) mitral valves from 12 symptomatic patients with severe mitral regurgitation who required mitral valve replacement and compared our findings with those in 13 control valves. The mean surface area of the “myxomatous” mitral valves (MMVs) was 1990 mm and of the control mitral valves (CMVs) was 760 mm2 (p < 0.001). The mean longest diameter of MMVs was 56.4 mm and of the CMVs was 36.8 mm (p < 0.001); the mean shortest diameter of MMVs was 44.8 mm and of CMVs was 22.7 mm (p < 0.001). The mean commissural diameter for MMVs was 50.4 mm and for CMVs was 30.0 mm (p < 0.001). The mean coapting line distance of MMVs was 34.1 mm and of CMVs 22.5 mm (p < 0.001). The mean surface area of the anterior cusp of MMVs was 910 mm2 and of CMVs was 560 mm2 (p < 0.01). The mean surface area of posterior leaflet was 927 mm2 in MMVs and 534 mm2 in CMVs (p < 0.02). CMV densities were nearly uniform (1.07 g/cm3), while the mean density of MMVs was 0.687 g/cm3 (p < 0.01). Dissolution of elastin was only slightly more frequent in MMVs than in CMVs. Myxomatous degeneration, noted in one‐half of CMVs, was found in chordae and pars fibrosa only in MMVs (p < 0.05). Mucopolysaccharide infiltration was more severe in all sites except the annulus in MMVs than in CMVs (p < 0.05). Fragmentation of collagen was severe in either the pars fibrosa or chorda of all MMVs, but was not seen in any CMV in these areas (p < 0.05). Gross morphology (increased surface area, increased diameter and decreased density) and histologic characteristics (collagen dissolution with myxomatous degeneration) allowed clear separation between CMVs and MMVs that produced severe mitral regurgitation. Collagen dissolution in the pars fibrosa and chordae was present only in MMVs, which suggests the primacy of collagen dissolution in mitral valves of patients with severe mitral regurgitation complicating the mitral valve prolapse syndrome. We therefore consider this process to be a disorder of collagen synthesis, content or organization (i.e., a dyscollagenosis).

Evidence for progression from mild to severe mitral regurgitation in mitral valve prolapse.

Little information is available concerning the progression of mild to severe mitral regurgitation (MR) in patients with mitral valve prolapse (MVP). This study reports 86 patients, average age 60 years, who presented with cardiac symptoms, precordial systolic murmur, severe MR and a high incidence of MVP on echocardiography (57 of 75 [75%] ) and left ventriculography (61 of 84 [73%] ). Seventy-five surgically excised mitral valves appeared grossly enlarged and floppy. Histologic studies showed extensive myxomatous changes throughout the leaflets and chordae. Eighty patients had had precordial murmurs first described at average age 34 years, but the average age at which symptoms of cardiac dysfunction appeared was 59. However, once symptoms developed, mitral valve surgery was required within 1 year in 67 of 76 patients who had undergone surgery. Atrial fibrillation, present in 48 of 86 patients (56%), or ruptured chordae tendineae, present in 39 of 76 patients (51%), may have contributed to this rapid progression and deterioration. Additionally, 13 patients had a remote history of documented infective endocarditis. Twenty-eight patients had at least 1 type of serial clinical evaluation that indicated progressive MR in all 28 patients on the basis of changing auscultatory findings (24 of 26), progressive radiographic cardiomegaly (24 of 25), echocardiographic left atrial enlargement (4.3 to 5 cm in 11 patients) and angiographically worsening MR (14 of 15). Twenty-four of these patients had evidence of MVP on at least 1 of their initial studies. Thus, mild MR due to MVP and myxomatous mitral valves is a progressive disease in some patients with MVP.

Delayed Sternal Closure after Cardiac Surgery

Fifty-seven patients undergoing various cardiac operations were managed with delayed sternal closure because of ongoing mediastinal hemorrhage or extreme cardiac dilatation. This strategy facilitated rapid access to the mediastinum for evacuation of clot when the risk of tamponade from hemorrhage was deemed great. When sternal closure over a dilated and edematous heart caused hemodynamically significant cardiac compression, wound closure without sternal reapproximation facilitated hemodynamic stability. Postoperative correction of hemodynamic and hemostatic functions allowed delayed sternal closure to be done a mean of 2.8 days later. Thirty-eight patients survived to leave the hospital. Recognized complications of delayed sternal closure included superficial wound infection (3 patients), sternal osteomyelitis (1 patient), and fatal mediastinal infection (1 patient). Delayed sternal closure may be beneficial in selected patients. Morbidity and mortality related to this technique have proved acceptable in this high-risk group.

Coronary artery fistula in the pediatric age group: A 19-year institutional experience

Ten patients with coronary artery fistulae were identified from records at Columbus Childrens Hospital between 1974 and 1993. Clinical presentations of patients were quite variable, from 1 day to 20 years of age. Symptoms ranged from none to severe cardiorespiratory failure requiring extracorporeal membrane oxygenation. Long term follow-up revealed one sudden death and one spontaneous closure of the fistula. This lesion should be ruled out in patients who present as extracorporeal membrane oxygenation candidates. Patients with mild forms of this lesion may be followed up medically if the left to right shunt is inconsequential, because spontaneous closure is a possibility. Because of the risk of sudden death, close long-term follow-up is mandatory even for operated patients, and antiplatelet therapy should be considered for these patients.

Primary Mediastinal Neoplasms in Infants and Children

Abstract Primary mediastinal tumors were observed in 62 infants and children. Thirty-nine of the tumors were located posteriorly, 16 anteriorly, and 7 in the middle mediastinum. Neurogenic tumors occurred in 36 patients, with neuroblastoma accounting for 25. Lymphoma was noted in 20 patients, teratoma in 5 patients, and a rare lipoma in 1. Overall, 47 patients had malignant tumors, and 16 survived. All 15 patients with benign tumors survived. Because of the high incidence of primary malignancy in this age group, all childhood mediastinal lesions should be explored. Although dismal results were obtained with lymphoma (1 patient is alive, a survival of 5%) a 56% survival (14 patients) was achieved with mediastinal neuroblastoma. Patients under 1 year of age with neuroblastoma had an 88% survival rate (8 of 9 patients). Those diagnosed after 1 year had a 37.5% survival rate (6 of 16). Results were more favorable with mediastinal lesions (56% survival) than with retroperitoneal neuroblastoma (19% survival), regardless of the patients age. Complete or partial extirpation and radiation therapy yielded the most success, while chemotherapy offered significant palliation.

Tricuspid stenosis. Atrial systolic murmur, tricuspid opening snap, and right atrial pressure pulse

Observations on the atrial systolic murmur, the tricuspid opening snap, and the right atrial pressure pulse of tricuspid stenosis are presented, based on catheter manometer intracardiac sound and pressure recordings in five patients with hemodynamically significant tricuspid stenosis. The manometer-recorded right atrial pressure pulse of tricuspid stenosis differed from the normal, with (1) elevation of right atrial pressure, (2) different morphologic features (tall, spiky A wave complete before C; small V wave with an interruption, the tricuspid opening snap notch at termination of the gradual Y descent; a diastolic plateau, the relatively flat diastolic segment of the right atrial pressure pulse following the tricuspid opening snap notch prior to the next A wave), and (3) the relative lack of right atrial pressure and right atrial pressure pulse response with normal respiration. The atrial systolic murmur, recorded in the right ventricular inflow tract, was complete by S1; the crescendo-decrescendo atrial systolic murmur configuration paralleled the right ventricular-right atrial diastolic pressure gradient at the time of the atrial A wave. The right atrial contraction-relaxation process, as reflected by the right atrial A wave ascent and descent, was complete at the onset of ventricular systole with P-R intervals of 170 to 200 msec. Thus, the timing and configuration of the atrial systolic murmur reflected the timing and completion of the right atrial contraction-relaxation process prior to the onset of right ventricular systole and the configuration of the tricuspid diastolic pressure gradient. The tricuspid opening snap was recorded in the right ventricular inflow tract and occurred at the time of a notch at the termination of the Y descent of the right atrial pressure pulse V wave, while right atrial pressure exceeded right ventricular pressure. The sound-pressure events were consistent with angiographic and echocardiographic studies, which showed doming or ballooning of the mobile, fused, stenotic tricuspid valve into the right ventricle during the Y descent of the right atrial pressure pulse. The tricuspid opening snap occurred at the time of the termination of the diastolic movement of the fused tricuspid unit into the right ventricle. These observations are presented within the framework of previous studies in order to trace the development of medical ideas about the pathophysiologic basis for the sound and pressure events of tricuspid stenosis.

Potential effect of lidocaine on ischemic myocardial injury: experimental and clinical observations.

The effect of lidocaine on ischemic myocardial injury was studied in acute myocardial infarction (AMI). In 20 anesthetized dogs coronary artery ligation (CAL) was performed. Dogs were divided into three groups. Group I (n = 8) had CAL only, Group II (n = 6) received 3 mg/kg of lidocaine (L) 30 min post-CAL, Group III (n = 6) received the same bolus injection of L and an L infusion of 2 mg/min for 120 min. In Group I the sum of ST segment elevation (Σ ST) and the number of sites showing >1 mV ST elevation (NST), as measured from epicardial mapping, were unchanged between 30 and 150 min post-CAL, the mean R magnitude decreased significantly, and 12 new Q waves were recorded. In Groups II and III, 15 min after L administration, Σ ST and NST decreased significantly (P < 0.05) and remained unchanged until the end of the study. There was no difference in Σ ST and NST changes between Groups II and III. No R wave magnitude changes or Q waves were observed between 30 and 150 min post-CAL in Groups II and III. Coronary sinus CPK at 150 min post-CAL increased more in Group II than in Group I (23 ± 3 vs 49.7 ± 9, P < 0.05). A negative inotropic effect was demonstrated by decreases in peak dp/dt (510 ± 50 mm Hg/sec, P < 0.05) and dQ/dt (28 ± 2%, P < 0.05) 5 min after the L bolus. This effect of lidocaine on Σ ST and NST was studied in six patients with anterior AMI. L decreased significantly both Σ ST and NST in the patients studied. These data suggest that lidocaine has a beneficial effect, decreasing ischemic injury and/or delaying the process of ischemic necrosis. This appears to be caused by a negative inotropic effect, which may be beneficial in the early post-open-heart surgery period and in patients with acute myocardial infarction.

Thrombotic Calcific Mitral Stenosis: Morphology of the Calcific Mitral Valve

We compared the morphology of the calcific stenotic mitral valve (CSMV) with noncalcific stenotic mitral valves (NCSMV) removed at surgery; control valves were obtained at autopsy. X-rays of the excised valves permitted localization and quantitation of calcification. A classification of CSMV applicable to noninvasive techniques based on this methodology is presented. Moderate to heavily CSMV had greater weight, volume, specific gravity, weight per area, with smaller orifice size when compared with NCSMV and controls. Leaflet mobility was obliterated in moderate to heavily CSMV, while most NCSMV had some degree of leaflet mobility.Surface morphology was strikingly different in CSMV with 1) surface ulceration, due to eruption of the underlying calcific focus through valvular endothelium, 2) thrombosis in the areas of ulceration ( associated with symptomatic arterial embolization in four patients), 3) whisker formation, filamentous stalks along the line of valve closure.Calcification in the CSMV is viewed as an active, progressive process resulting in altered physical characteristics of the valve, progressive leaflet immobility and orifice narrowing, and eruptive surface changes with thrombus formation and arterial embolization arising from the CSMV itself. Clinical implications and a rationale for more precise classification of mitral stenosis on the basis of valvular calcification are presented.