Norman A. Silverman

Carcinoid tumors of the thymus

Carcinoid tumors arising in the thymus are rare. Since Rosai and Higa in 1972 distinguished these neoplasms from thymomas, fewer than 100 cases have been reported in the world literature. In a 38-year review (1950 to 1988) of surgically treated thymic tumors at Henry Ford Hospital, only 7 cases of thymic carcinoids were identified. These 6 men and 1 woman ranged in age from 27 to 70 years (mean, 48 years) at diagnosis. Follow-up was available in all patients with the longest survival being 12 years in 2 patients, and the shortest, 1 year, in 1. Recurrences and/or metastases developed in 4 of 7 patients between 1 and 9 years after initial resection. Recurrences were treated by reexcision in addition to radiation treatment and chemotherapy in 3 patients and reexcision with radiation treatment alone in 1 patient. A review of the literature along with our experience suggests that thymic carcinoids have a biological behavior distinct from thymoma in terms of cell origin, associated syndromes, neoplastic behavior, and prognosis. An aggressive surgical approach with complete initial excision of the tumor and of subsequent recurrences, along with radiation and probably chemotherapy, is the best available treatment today.

A randomized, double-blind comparison of intravenous diltiazem and digoxin for atrial fibrillation after coronary artery bypass surgery

BACKGROUND Atrial fibrillation (AF) after coronary bypass graft surgery may result in hypotension, heart failure symptoms, embolic complications, and prolongation in length of hospital stay (LOHS). The purpose of this study was to determine whether intravenous diltiazem is more effective than digoxin for ventricular rate control in AF after coronary artery bypass graft surgery. A secondary end point was to determine whether ventricular rate control with diltiazem reduces postoperative LOHS compared with digoxin. METHODS AND RESULTS Patients with AF and ventricular rate > 100 beats/min within 7 days after coronary artery bypass graft surgery were randomly assigned to receive intravenous therapy with diltiazem (n = 20) or digoxin (n = 20). Efficacy was measured with ambulatory electrocardiography (Holter monitoring). Safety was assessed by clinical monitoring and electrocardiographic recording. LOHS was measured from the day of surgery. Data were analyzed with the intention-to-treat principle in all randomly assigned patients. In addition, a separate intention-to-treat analysis was performed excluding patients who spontaneously converted to sinus rhythm. In the analysis of all randomly assigned patients, those who received diltiazem achieved ventricular rate control (> or = 20% decrease in pretreatment ventricular rate) in a mean of 10 +/- 20 (median 2) minutes compared with 352 +/- 312 (median 228) minutes for patients who received digoxin (p < 0.0001). At 2 hours, the proportion of patients who achieved rate control was significantly higher in patients treated with diltiazem (75% vs 35%, p = 0.03). Similarly, at 6 hours, the response rate associated with diltiazem was higher than that in the digoxin group (85% vs 45%, p = 0.02). However, response rates associated with diltiazem and digoxin at 12 and 24 hours were not significantly different. At 24 hours, conversion to sinus rhythm had occurred in 11 of 20 (55%) patients receiving diltiazem and 13 of 20 (65%) patients receiving digoxin (p = 0.75). Results of the analysis of only those patients who remained in AF were similar to those presented above. There was no difference between the diltiazem-treated and digoxin-treated groups in postoperative LOHS (8.6 +/- 2.2 vs 7.7 +/- 2.0 days, respectively, p = 0.43). CONCLUSIONS Ventricular rate control occurs more rapidly with intravenous diltiazem than digoxin in AF after coronary artery bypass graft surgery. However, 12- and 24-hour response rates and duration of postoperative hospital stay associated with the two drugs are similar.

Estimation of total body and extracellular water in post-coronary artery bypass graft surgical patients using single and multiple frequency bioimpedance.

OBJECTIVE To assess the value of bioimpedance as a clinical tool by determining the accuracy and bias of single and multiple frequency bioimpedance estimates of total body and extracellular water in comparison with values established by criterion reference techniques. DESIGN Controlled, prospective, single-blind investigation. SETTING Private, not-for-profit, university-affiliated, acute care hospital. PATIENTS Eight male, post-elective coronary artery bypass graft surgical patients. INTERVENTIONS Within 6 hrs after surgery, estimates of total body and extracellular water volumes were determined using single and multiple frequency bioimpedance techniques. These estimates were then compared with the gold standard volumes measured by deuterium oxide and bromine dilutional space determination, respectively. MEASUREMENTS AND MAIN RESULTS The mean multiple frequency bioimpedance estimate of total body water of 47.7 +/- 9.4 L was statistically different from the single frequency bioimpedance and deuterium values of 52.5 +/- 9.4 (p < .006) and 53.3 +/- 11.6 L (p < .002), respectively. In comparison, the mean multiple and single frequency bioimpedance estimates of extracellular water, 26.3 +/- 5.4 and 29.2 +/- 5.4 L, respectively, were not statistically different from the bromine value of 27.5 +/- 6.9 L. In addition, the mean errors for multiple and single frequency bioimpedance determinations of extracellular water, -1.2 +/- 2.0 and 1.7 +/- 2.7 L, respectively, were statistically different (p = .001). CONCLUSIONS In male, post-elective coronary artery bypass graft surgical patients, single frequency bioimpedance was a more accurate and less biased predictor of total body water than multiple frequency bioimpedance. The accuracy and bias of multiple frequency bioimpedance was superior to single frequency bioimpedance for the prediction of extracellular water. Whether this observation remains true for other populations of critically ill patients remains to be investigated.

Coronary flow reserve after ischemia and reperfusion of the isolated heart: Divergent results with crystalloid versus blood perfusion

Mechanical function and coronary hemodynamics were assessed in 73 isolated rabbit hearts randomly subjected to 0, 10, 20, 30, or 45 minutes of 37 degrees C global ischemia and 45 minutes of reperfusion in either a modified Krebs buffer or homologous blood-perfused Langendorff mode (n = 7 to 9 hearts per group). Isovolumic developed pressure, resting coronary flow, and response to endothelium-dependent (bradykinin) and -independent (nitroglycerin) agonists were quantitated at defined preload and heart rate. Perfusate did not influence systolic performance, which was impaired after 30 minutes of ischemia and fell to 64% to 72% of preischemic values after 45 minutes of ischemia (p < 0.05). However, basal coronary flow was at least sixfold greater in crystalloid-perfused hearts. Moreover, coronary hyperemia (p < 0.05) persisted for Krebs-perfused hearts subjected to all but the longest ischemic interval. After equilibration, all postischemic blood-perfused hearts had basal flow unchanged from before ischemia. Bradykinin and nitroglycerin induced similar increases in coronary flow for each group before and after each ischemia interval. However, the magnitude of this increase was greater in blood-perfused hearts (p < 0.01) and was not attenuated by the ischemic times encompassed in this protocol. In contrast, endothelium-dependent and -independent coronary flow reserve was abolished after 20 minutes of ischemia or longer in Krebs-perfused hearts. These data suggest that the unphysiologic resting flow patterns of crystalloid-perfused isolated hearts obfuscate interpretation of the interaction between coronary flow reserve and ischemic injury.

Transesophageal echocardiographic features of normal and dysfunctioning bioprosthetic valves

Transesophageal and transthoracic echocardiography and color flow Doppler were performed in patients with 42 normal and 20 dysfunctioning bioprosthetic mitral and aortic valves. Transesophageal echocardiography was superior to the transthoracic approach in delineating bioprosthetic valve cusps and the presence of valve thickening due to valve degeneration. In 27 clinically normal bioprosthetic mitral valves, regurgitation was demonstrated in three patients by the transthoracic approach and in seven by transesophageal study. Both transesophageal and transthoracic color flow Doppler demonstrated mitral regurgitation in 17 clinically regurgitant valves. The severity of mitral regurgitation was accurately assessed by the transesophageal study in all 13 patients who underwent angiography, whereas the transthoracic imaging underestimated valvular regurgitation in 7 of the 13 cases (54%). Bioprosthetic aortic valves were normal on clinical examination in 15 patients and were regurgitant in three others. Both transthoracic and transesophageal color flow Doppler were of equal value in observing and quantifying aortic regurgitation. In five clinically normal and regurgitant mitral and aortic valves, transesophageal color flow Doppler revealed eccentric regurgitant jets suggestive of paravalvular leak. This feature was not evident by the transthoracic approach. In conclusion, transesophageal echocardiography and color flow Doppler are superior to transthoracic imaging in estimating bioprosthetic mitral, but not aortic regurgitation, in differentiating valvular from paravalvular regurgitation, and in demonstrating thickened valves due to cusp degeneration.

Acute renal failure in cardiothoracic surgery patients: what is the best definition of this common and potent predictor of increased morbidity and mortality

BACKGROUND Universal agreement on criteria for acute renal failure (ARF) is lacking. The purpose of the current study was to determine which of 6 definitions for ARF best predicted clinical outcomes in postoperative cardiothoracic surgery (CTS) patients. METHODS Criteria for ARF were retrospectively applied to 1,085 CTS patients. General linear models analyzed length of stay (LOS) and ventilator days with logistic regression for mortality. RESULTS Thirty-seven percent of patients met at least 1 of 6 definitions of ARF. For each 1-mg/dL increase from the initial creatinine, LOS increased by 6.96 days, ventilator days increased by 3.58 days, and mortality increased by 2.23 times (P < .0001). CONCLUSIONS One definition that best predicted ARF was not found. ARF was a significant independent predictor of increased mortality, LOS, and ventilator days. Even small increases in creatinine correlate with clinically significant worsening of expected outcomes.

Enrollment in the Health Alliance Plan HMO Is Not an Independent Risk Factor for Coronary Artery Bypass Graft Surgery

BACKGROUND Henry Ford Hospital is the sole provider of cardiac surgical services for the Health Alliance Plan, a health maintenance organization (HMO) that presently serves 450,000 enrollees. METHODS AND RESULTS To determine the effect of managed care referral patterns on the outcome of coronary artery bypass graft (CABG) surgery, we retrospectively reviewed two concurrent groups of patients, 569 HMO patients and 225 patients with free-for-service (FFS) insurance, who had undergone isolated primary CABG surgery between January 1, 1990 and January 31, 1994. The 605 patients with Medicare operated on during the same time frame were excluded to obviate age bias. Age, sex, use of cardiac medications, history of prior percutaneous transluminal coronary angioplasty or thrombolytic therapy, history of recent and remote myocardial infarction, extent of coronary disease, presence of preexisting comorbid conditions, and incidence of unstable clinical syndromes and left ventricular dysfunction (ejection fraction < 40%) were comparable for both groups. In hospital mortality (HMO group, 1.9%; FFS group, 2.2%), mean ICU stay (HMO, 2.6 +/- 0.3 days; FFS, 2.3 +/- 0.3 days), and total hospital length of stay (HMO, 9.8 +/- 0.8 days; FFS, 8.6 +/- 0.6 days) were likewise similar. CONCLUSIONS These data refute the notion that the gate-keeper mentality often associated with managed-care health insurance vehicles results in delayed referral of patients with coronary artery disease and results in suboptimal outcome.

Mitral Annular Calcification Mimicking an Intracardiac Mass

We present two patients with atypical mitral annular calcification. In both instances, the annular calcification presented as a mass localized to the atrioventricular junction. In one instance, there was a mobile element of the mass which resulted in an embolic stroke. In conclusion, atypical mitral annular calcification can mimic an intracardiac mass. It is usually recognized by its typical location and echocardiographic characteristics.

Treatment of Postoperative Atrial Fibrillation

Postoperative atrial fibrillation can occur in approximately 30% of patients. Although often a benign complication, it can result in significant morbidity and prolong hospitalization with attendant increased expenditure of health care resources. A rigid approach for prophylaxis and treatment is illogical, but with separate focus on rate control and cardioversion, a sinus mechanism can be safely and reliably achieved with minimal patient discomfort.

Apical left ventricular lipoma presenting as syncope.

1 I-second pause (Fig. 1). After the sinus pause, a marked decrease in waveform amplitude was noted bilaterally on the EEG followed by low-amplitude generalized fast activity, which corresponded clinically to tonic-clonic seizure activity. Thirty seconds after the onset of the seizure and the return of the heart rate to baseline, there was cessation of seizure activity clinically and on EEG. A permanent VVI pacemaker was implanted the following day without complications. Telemetry monitoring after insertion of a pacemaker revealed no further episodes of bradycardia. The patient has had no further episodes of syncope or seizure activity during 14 months of follow-up. Although loss of consciousness as a result of inadequate cardiac output is a common symptom associated with cardiac arrhythmias, frank seizure activity is a rare occurrence.z-s This is the first report in which a seizure precipitated by a period of asystole was documented by standard, simultaneous EEG and ECG recordings. As illustrated by this case, a marked reduction in EEG amplitude after the period of asystole is characteristic of cerebral ischemia and is the likely precipitant of the seizure. Without the use of simultaneous EEG and ECG monitoring, a correct diagnosis could not have been made. Thus all adults with a newonset seizure disorder, in whom routine EEG is nondiagnostic, should have a careful cardiac and neurologic evaluation, This is particularly relevant in elderly persons who may have unsuspected conduction system disease. The use of simultaneous EEG and ECG recordings or ambulatory EEG and ECG monitoring may provide useful diagnostic information and allow the physician to institute appropriate therapy.