Is cardiac MRI an effective test for arrhythmogenic right ventricular cardiomyopathy diagnosis?

AIM: To evaluate the referrals with suspected arrhythmogenic right ventricular cardiomyopathy (ARVC) and compare cardiac MR (cMR) findings against clinical diagnosis. METHODS: A retrospective analysis of 114 (age range 16 to 83, males 55% and females 45%) patients referred for cMR with a suspected diagnosis of ARVC between May 2006 and February 2010 was performed after obtaining institutional approval for service evaluation. Reasons for referral including clinical symptoms and family history of sudden death, electrocardiogram and echo abnormalities, cMR findings, final clinical diagnosis and information about clinical management were obtained. The results of cMR were classified as major, minor, non-specific or negative depending on both functional and tissue characterisation and the cMR results were compared against the final clinical diagnosis. RESULTS: The most common reasons for referral included arrhythmias (30%) and a family history of sudden death (20%). Of the total cohort of 114 patients: 4 patients (4%) had major cMR findings for ARVC, 13 patients (11%) had minor cMR findings, 2 patients had non-specific cMR findings relating to the right ventricle and 95 patients had a negative cMR. Of the 4 patients who had major cMR findings, 3 (75%) had a positive clinical diagnosis. In contrast, of the 13 patients who had minor cMR findings, only 2 (15%) had a positive clinical diagnosis. Out of the 95 negative patients, clinical details were available for 81 patients and none of them had ARVC. Excluding the 14 patients with no clinical data and final diagnosis, the sensitivity of the test was 100%, specificity 87%, positive predictive value 29% and the negative predictive value 100%. CONCLUSION: CMR is a useful tool for ARVC evaluation because of the high negative predictive value as the outcome has a significant impact on the clinical decision-making.

Paramedic decision making: prehospital thrombolysis and beyond.

BACKGROUND: Mortality from acute myocardial infarction is influenced by the speed at which reperfusion therapy is delivered. In the U.K., prehospital thrombolysis (PHT), administered by paramedics, has been developed to improve call to needle (CTN) times. Recently, it has been shown in randomised trials that mortality can be further reduced by primary percutaneous coronary intervention (PPCI). This project was developed to assess current ST-elevation myocardial infarction practice in a district general hospital and to prepare paramedics for PPCI. METHODS: Data were collected prospectively over a 12-month period for all patients who received thrombolysis for a presumed myocardial infarct. The primary outcome measures for each case were who delivered the thrombolysis, either the paramedic crew or the hospital, and if the patient did not receive PHT the reason why not. Secondary outcome measures included the CTN time. RESULTS: 153 patients received thrombolysis over the time period (99 men, 54 women, mean age 66 ± 15 years). Of this group, 55 patients received PHT (35.9%) with a median CTN time of 36 min (inter-quartile range (IQR) 30-42 min). The commonest reason for exclusion from receiving PHT was that the patient's history did not fit the eligibility criteria (25% of cases). CONCLUSIONS: Paramedics are able to deliver PHT promptly and safely. With the focus now on PPCI, it is anticipated that not only will paramedics be able to select patients for delivery to a heart attack centre for PPCI, they will be selecting many more patients for this treatment than have up to now received PHT.

Characterization of the vasodilatory action of testosterone in the human pulmonary circulation.

AIM: To assess for the first time the vasodilatory effect of testosterone in the human pulmonary circulation utilizing both isolated human pulmonary arteries and isolated perfused human lungs. In addition, a secondary aim was to determine whether there was any difference in the response to testosterone dependent upon gender. METHODS: Isolated human pulmonary arteries were studied by wire myography. Vessels were preconstricted with U46619 (1 nM-1 microM) prior to exposing them to either testosterone (1 nM-100 microM) or ethanol vehicle (<0.1%). Isolated lungs were studied in a ventilated and perfused model. They were exposed to KCl (100 mM), prior to the addition of either testosterone (1 nM-100 microM) or ethanol vehicle (<0.1%). RESULTS: Testosterone caused significant vasodilatation in all preparations, but a greater response to testosterone was observed in the isolated perfused lungs, 24.9 +/- 2.2% at the 100 microM dose of testosterone in the isolated pulmonary arteries compared to 100 +/- 13.6% at the 100 microM dose in the isolated perfused lungs. No significant differences in the response to testosterone were observed between sexes. CONCLUSION: Testosterone is an efficacious vasodilator in the human pulmonary vasculature and this is not modulated by patient sex. This vasodilator action suggests that testosterone therapy may be beneficial to male patients with pulmonary arterial hypertension.