Significance of ST depression during exercise treadmill stress and adenosine infusion myocardial perfusion imaging.

BACKGROUND: ST segment depression on the electrocardiogram during the exercise treadmill test (ETT) is used as a predictor of coronary artery disease (CAD), although it is recognised that both false-positive and false-negative results limit the value of this procedure. Although adenosine does not produce an inotropic or chronotropic effect upon the myocardium it may cause ST depression during infusion. METHODS: The 12-lead ECG recordings obtained during 825 adenosine stress and 425 ETT procedures, performed as part of a 2-day Tc-MIBI protocol, were retained for examination and comparison with the appearances at subsequent myocardial perfusion imaging (MPI). RESULTS: ST depression was associated with 44 (4.9%) of the adenosine stress and 44 (10.4%) of the ETT procedures. Both 1 and 2 mm ST depression during adenosine stress were significant predictors of reversible ischaemia (p < 0.01; p < 0.01). However, even though 2 mm ST depression on ETT was significant as a predictor of reversible ischaemia (p < 0.01), 1 mm ST depression on ETT was not (p = 0.4). There were more female cases with false positive ECG changes in both the adenosine stress (63.6%) group and the ETT (66.7%) group. There was no significant correlation between the territory of the ischaemic changes seen on the ECG with the location of defects developing on MPI in both the adenosine stress and ETT groups. CONCLUSIONS: ST depression of 1 mm occurring with adenosine stress, unlike with the ETT, is a significant predictor of ischaemia.

The natriuretic peptides and their role in disorders of right heart dysfunction and pulmonary hypertension.

Atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) are increased in conditions with cardiac ventricular volume and pressure overload. The general physiological and potential therapeutic roles of natriuretic peptides in respiratory disease, right ventricular (RV) dysfunction, and pulmonary arterial hypertension (PAH) are reviewed. BNP levels can be used to differentiate between dyspneic patients with a pure respiratory defect and those with RV dysfunction. BNP levels also correlate with mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance (PVR) in patients with PAH (atrial septal defect, chronic thromboembolic disease, and scleroderma). BNP is a predictor of mortality in patients with primary pulmonary hypertension (PPH). These are important clinical implications in that a noninvasive blood test may be used to identify high-risk patients for more invasive procedures such as cardiac catheterization. BNP or NT-proBNP measurements may also be used to guide therapy (e.g., pulmonary vasorelaxants) in PAH since upregulation of the natriuretic peptide pathway has been shown to reduce cardiac hypertrophy and PAH. Additionally, there may be therapeutic potential via recombinant BNP or neutral endopeptidase inhibitors in RV dysfunction and PAH.

A comparison of wide local excision with abdominoperineal resection in anorectal melanoma.

Anorectal melanoma is a rare condition and its surgical management is controversial. Seventeen large case series from over the past 10 years were reviewed. The survival of patients treated by either abdominoperineal resection (APR) or wide local excision (WLE) was analysed according to the stage of the disease. Comparison of the survival of patients who underwent APR with those who underwent WLE showed no statistically significant advantage for either procedure in patients at all disease stages. APR should therefore only be performed when local excision is not possible or for palliative purposes.