Electrocardiographic changes in acute perimyocarditis

Pericarditis and myocarditis are characterised by electrocardiographic changes and elevated cardiac enzymes, respectively, and patients with perimyocarditis often complain of chest discomfort. These findings are nonspecific and often lead to diagnostic difficulties, as ST-elevation myocardial infarction commonly presents in a similar fashion. Clinical differentiation between perimyocarditis and myocardial infarction are especially important because adverse side effects can occur if reperfusion therapy is administered for a patient with acute pericarditis or if a diagnosis of acute myocardial infarction is missed. We herein describe a case of perimyocarditis with ST elevation and raised cardiac markers, which led to two emergency coronary angiographies that were subsequently found to be normal. We include the three serial electrocardiographies (ECGs) performed to show the characteristic features of perimyocarditis and further discuss the importance of identifying typical and atypical ECG features of pericarditis.     

Percutaneous cardiopulmonary bypass: application and indication for use

Percutaneous cardiopulmonary bypass (CPB) was used in 22 patients: 7 patients with cardiac arrest due to acute myocardial infarction; 4 patients in cardiac arrest because of failed angioplasty; 1 patient for high-risk elective angioplasty; 1 patient with massive pulmonary emboli; 2 patients with hypothermia; 2 pediatric patients (1 with sepsis and 1 in combination with extracorporeal membrane oxygenator support); 1 patient with refractory arrhythmia; and 4 patients with trauma. Percutaneous CPB involves a modified Seldinger technique that is easily applied. All patients except those with massive trauma were resuscitated with the use of percutaneous CPB. One patient requiring a very difficult proposed angioplasty received percutaneous CPB support while triple-vessel angioplasty was performed. Percutaneous CPB appears to be beneficial in resuscitating patients with refractory cardiac arrest or other forms of circulatory collapse except trauma. Limited use for brief periods in high-risk patients having elective angioplasty might be applicable.     

Permanent left ventricular assistance for outpatients through surgical implantation of a modified intra-aortic balloon pump

There is a large population of patients in end-stage congestive heart failure who cannot be treated by means of conventional cardiac surgery, cardiac transplantation, or chronic catecholamine infusions. In 2 such patients, we provided permanent left ventricular assistance on an outpatient basis by surgically implanting a modified intra-aortic balloon pump. A Dacron-velour graft to the common iliac artery served as a covering for the extravascular portion of the balloon's pneumatic tubing, which was stabilized by routing it through the iliac crest. The tubing was then carried ventrally to exit through a stoma just above the inguinal ligament. Before hospital discharge, each patient underwent a 5-day regimen of alternate pumping and ambulation. The patient was then permitted to go home, but returned daily as an outpatient in accordance with individual need, for approximately 6 hours of hemodynamic support. The 1st patient lived 3 months after pump insertion, and the 2nd patient for 38 days. Although the 1st patient developed a fever of unknown origin that prompted us to remove the intra-aortic balloon pump unnecessarily, there was no evidence of infection upon surgical exploration and subsequent tissue culturing; she died, rather, of intractable ventricular fibrillation, apparently consequent to her 36-hour loss of hemodynamic support. The 2nd patient also died of a cause unrelated to the presence of the pump, and on autopsy showed good evidence of healing and absence of infection. On the evidence of this pilot study, we conclude that intermittent left ventricular assistance, through periodic activation of a permanently implanted intra-aortic balloon pump during outpatient visits, warrants further study as an alternative for selected patients with end-stage heart disease, when medical and other surgical options have been exhausted.     

Reperfusion protocol and results in 738 patients with evolving myocardial infarction

Reperfusion is an accepted therapy for evolving myocardial infarction (MI), as successful reperfusion reduces morbidity and mortality. A team approach between the cardiologists and cardiac surgeons must be applied to achieve reperfusion within a finite time from the onset of coronary thrombosis. Analysis of 738 patients grouped them by successful reperfusion in the catheterization laboratory versus the operating room. Factors that predict wall motion recovery related to the onset of clinical symptoms, time to reperfusion, coronary anatomy, and collateral network were reviewed. Comparisons were made between patients with stable versus unstable hemodynamics and successful or unsuccessful reperfusion. Of the 738 patients, the initial attempt at reperfusion was made in the catheterization laboratory with success in 331. These patients all had primarily single-vessel disease. With multiple-vessel disease identified at catheterization, 189 patients were immediately treated by surgical reperfusion. This method also was used for an additional 72 patients in whom reperfusion could not be achieved in the catheterization laboratory. Of the entire group of 738 patients, 146 (20%) could not be reperfused. Overall mortality for the 592 patients reperfused was 4.9% compared with 17% for those who could not be reperfused. Time was critical for wall motion recovery if no collaterals were demonstrated on angiography. If collaterals were present, time to reperfusion was not critical. Wall motion recovered in 90% of the patients if the endocardial anatomy on the initial angiogram was smooth. However, if the endocardial anatomy looked mottled and irregular, less than 10% of patients had recovery of wall motion.(ABSTRACT TRUNCATED AT 250 WORDS)     

Immunohistochemistry for Merkel cell polyomavirus is highly specific but not sensitive for the diagnosis of Merkel cell carcinoma in the Australian population

Recent studies have demonstrated a high frequency of detection of Merkel cell polyomavirus in Merkel cell carcinoma. However, most of these studies are from European or North American centers that have relatively low sun exposure and may have a higher incidence of virus-driven oncogenesis compared with the highly sun-exposed but predominantly fair-skinned Australian population. We performed immunohistochemistry for Merkel cell polyomavirus on 104 cases of Merkel cell carcinoma and 74 cases of noncutaneous small cell–undifferentiated carcinoma from 3 major Australian centers. Nineteen (18.3%) cases of Merkel cell carcinoma showed positive staining for Merkel cell polyomavirus versus 1 (1.3%) of small cell–undifferentiated carcinoma. All 15 cases (14.3%) of Merkel cell carcinoma with areas of mixed squamous differentiation showed negative staining. We found positive staining in only 3 (7.7%) of 39 Merkel cell carcinoma from the head and neck (the most sun-exposed area) versus 16 (24.6%) of 65 of tumors from other sites (P < .05). Our findings support the concept of a Merkel cell polyomavirus–driven and a non-Merkel cell polyomavirus–driven (primarily sun-dependent) pathway in Merkel cell carcinoma carcinogenesis, with the latter being significantly more frequent in Australia and in mixed squamous–Merkel cell carcinoma (which is also more frequent in Australia). Although immunohistochemistry for Merkel cell polyomavirus seems to be highly specific in all populations, the low incidence of Merkel cell polyomavirus–positive Merkel cell carcinoma in a highly sun-exposed population limits its diagnostic utility in this setting.