Cardiac MRI: estimation of changes in normalized myocardial gadolinium accumulation over time after contrast injection in patients with acute myocarditis and healthy volunteers

PURPOSE

An increased normalized gadolinium accumulation (NGA) in the myocardium during early washout has been used for the diagnosis of acute myocarditis (AM). Due to the fact that the pharmacokinetics of contrast agents are complex, time-related changes in NGA after contrast injection are likely. Because knowledge about time-related changes of NGA may improve the diagnostic accuracy of MR, our study aimed to estimate the time course of NGA after contrast injection in patients as well as in healthy volunteers.

MATERIALS AND METHODS

An ECG-triggered inversion recovery SSFP sequence with incrementally increasing inversion times was repetitively acquired over the 15 minutes after injection of 0.2 Gd-DTPA per kg body weight in a 4-chamber view in 15 patients with AM and 20 volunteers. The T 1relaxation times and the longitudinal relaxation rates (R1) of the myocardium and skeletal musculature were calculated for each point in time after contrast injection. The time course of NGA was estimated based on the linear relationship between R1 and tissue Gd concentration.

RESULTS

NGA decreased over time in the form of a negative power function in patients with AM and in healthy controls. NGA in AM tended to be higher than in controls (p > 0.05).

CONCLUSION

NGA rapidly changes after contrast injection, which must be considered when measuring NGA. Although we observed a trend towards higher NGA values in patients with AM with a maximum difference one minute after contrast injection, NGA did not allow us to differentiate patients with AM from healthy volunteers, because the observed differences did not reach a level of significance.

[Successful implementation of an "in-hospital resuscitation team" in a university hospital]

BACKGROUND AND OBJECTIVE

Resuscitation is the most important emergency action in a life-threatening cardiopulmonary arrest. The organizational, personnel and equipment requirements for an optimal treatment of emergency patients in a university hospital are described, as well as the short- and mid-term results.

PATIENTS AND METHODS

Retrospective analysis of 132 cases of cardiopulmonary resuscitation based on a two-pages reporting form whose completion by the involved physician and intensive care nurse is mandatory after each event.

RESULTS

About 65 % of all events were triggered by cardiac and respiratory causes. In 50 % of all cases there was an acute life-threatening situation, requiring an intubation in 46 % and mechanical reventilation in 42 % of all cases. One third of all patients who were successfully reanimated were discharged alive from hospital after the intensive care treatment.

CONCLUSION

A well organized and adequately equipped resuscitation team is the basis for achieving optimal chances of survival in life-threatening emergencies. This is especially so in large university hospitals with often care for patients with multiple morbidities.

Arrhythmogenic right ventricular cardiomyopathy/dysplasia: a review and update

Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is a predominantly genetically determined and heritable form of cardiomyopathy that is characterized pathologically by the replacement of myocytes by adipose and fibrous tissue and leads to right ventricular failure, arrhythmias, and sudden cardiac death. The estimated prevalence of ARVC/D in the general population ranges from 1 in 2,000 to 1 in 5,000, men are more frequently affected than women, with an approximate ratio of 3:1. ARVC/D can be inherited as an autosomal dominant disease with reduced penetrance and variable expression, autosomal recessive inheritance is also described. There have been 12 genes identified which are linked to ARVC/D, encoding several components of the cardiac desmosome. Dysfunctional desmosomes resulting in defective cell adhesion proteins, such as plakoglobin (JUP), desmoplakin (DSP), plakophilin-2 (PKP-2), and desmoglein-2 (DSG-2) consequently cause loss of electrical coupling between cardiac myocytes, leading to myocyte cell death, fibrofatty replacement and arrhythmias. Diagnosis is based on the finding a combination of characteristic abnormalities in family history, electrocardiography, cardiac imaging as well as endomyocardial biopsy (original task force criteria). Therapeutic options remain limited because of the progressive nature of ARVC/D. Competitive athletics should be avoided. Patients with ARVC/D with a history of having been resuscitated from sudden cardiac death, patients with syncope, very young patients, and those who have marked right ventricular involvement are at the highest risk for arrhythmic death and also, the presence of left ventricular involvement is a risk factor. Several authors concluded that patients who meet the Task Force criteria for ARVC/D are at high risk for sudden cardiac death and should undergo ICD placement for primary and secondary prevention, regardless of electrophysiologic testing results. The role of electrophysiologic study and VT catheter ablation in ARVC/D remains poorly defined, and is frequently used as a palliative measure for patients with refractory VT. The progressive nature of ARVC/D suggests that catheter ablation would not be a long-term curative procedure. Sotalol proved to be highly effective in patients with ARVC/D and inducible as well as non-inducible ventricular tachycardia; if it is ineffective in inducible ventricular tachycardia response to other antiarrhythmic drugs is unlikely and therefore non-pharmacological therapy without further drug testing should be considered. Orthotopic heart transplantation is considered in patients with progressive heart failure and intractable recurrent ventricular arrhythmias.

[Infective endocarditis as cardiovascular emergency]

Infective endocarditis is an infection of cardiovascular structures which is typically caused by bacteria. Despite recent medical advances mortality reaches up to 26% which is even higher with mortality rates of up to 84% in complex cases leading to admission to intensive care units. The diagnosis is based on positive blood culture results with identical microorganisms and the demonstration of endocardial involvement. A rapid initiation of an adequate therapeutic regimen is important to prevent the patients from severe complications such as heart failure, uncontrolled infection or septic embolism. An early and targeted initiation of an antibiotic therapy after microbiologic testing is crucial for therapeutic success. The immediate cooperation of Cardiologists, Microbiologists, Infectious Disease Specialists and Cardiac Surgeons is highly recommended to allow an adequate medical and surgical treatment without delay in complex cases. Antibiotic treatment has to be continued postoperatively.

[Home monitoring of an incessant VT in an ICD patient]

Due to the increasing number of patients and complexity of modern tachycardia devices, efficient therapy monitoring as offered by telemedicine monitoring is of increasing importance. The potential advantages of remote control for patient management include early detection of device-related technical problems and arrhythmias. We report the case of an ICD patient with incessant ventricular tachycardia in whom immediate arrhythmia transmission was monitored by remote control.

[Coronary artery disease in HIV-infected subjects. Results of 101 coronary angiographies]

BACKGROUND

The introduction of antiretroviral therapy has brought cardiac disease as a comorbidity in HIV-infected patients in particular into focus. The present study analyses the results of coronary angiography in this patient population.

METHODS

Over a time period of 12 years, 101 coronary angiographies were performed in HIV-infected patients. A retrospective analysis included demographic parameters, cardiac history, cardiovascular risk factors, HIV-specific parameters including antiretroviral therapy and the results of coronary angiographies.

RESULTS

Of the subjects included in the study, 89% were men. The mean age in the analysed population was 50.2 years at the time of coronary angiography. Patients had an elevated rate of cardiovascular risk factors including diabetes mellitus (15.9%), arterial hypertension (65.9%), hyperlipidemia (56.8 %) and smoking (68.2 %). Primary coronary angiography demonstrated coronary disease in 59.1%. Of all patients with coronary artery disease, 70% underwent coronary intervention. Subjects who underwent coronary intervention exhibited hyperlipidemia significantly more often (77.8% vs. 42.3%, p=0.02). Cardiovascular risk factors play a prominent role in the development of premature arteriosclerosis in HIV-infected patients. Furthermore, our data highlight the importance of invasive diagnostics in this patient group.

[Successful treatment of secondary aortoesophageal fistula after thoracic endovascular aortic repair]

HISTORY AND CLINICAL SYMPTOMS: A 58-year-old man was admitted to our hospital with acute chest pain and subfebrile temperatures. Two years ago, endovascular aortic stent-graft placement had been performed for acute type B aortic dissection complicated by malperfusion syndrome.

DIAGNOSTIC ASSESSMENT

CT angiography showed a discrete soft-tissue attenuation mass between the aorta and esophagus. The patient developed progressive swallow disorder and esophago-gastro-duodenoscopy demonstrated deep esophageal ulcerations at the level of the implanted aortic stent-graft. Intravenous treatment with broad spectrum antibiotics was started. The FDG-PET/CT scan showed increased FDG uptake and air entrapment in the affected region establishing the diagnosis of aortoesophageal fistula formation.

THERAPY AND OUTCOME

Given the generally poor condition of the patient and the high risk of any aggressive surgical intervention, a new limited surgical approach was chosen consisting of open transthoracic esophageal resection, blind closure of the stomach and cervical esophagostomy. A percutaneous endoscopic gastrostomy tube was placed. After three months, esophageal continuity was restored by retrosternal colon interposition. The presented therapeutic management resulted in a full recovery of the patient.

CONCLUSION

Aortoesophageal fistula is a rare complication of thoracic aortic stent-graft placement. Patient may present with unspecific symptoms such as fever and rised inflammatory markers, but may also present with massive upper gastrointestinal bleeding. The herein presented limited therapy with esophageal resection represents a promising to the otherwise difficult therapy of aortoesophageal fistula.