Roberto Kalil

Análise da dispersão do intervalo QT em pacientes com infarto agudo do miocárdio: efeito da reperfusão coronariana

OBJECTIVEnTo study the effect of early reperfusion of infarct-related artery on QT(DeltaQT) dispersion interval, as well as how valuable it is as a marker for coronary reperfusion and ventricular arrhythmias.nnnMETHODSnOne hundred and six patients with reperfusion (WR) and 48 without reperfusion (WtR) who have received thrombolytic therapy in the acute phase of infarction were studied. ECG carried out on admission as well as on day 4 of patients course were analyzed. DeltaQT - defined as the difference between maximum and minimum QT interval - was measured by 12-lead ECG.nnnRESULTSnThe reperfusion group showed significant DeltaQT reduction - from 89.66+/-20.47ms down to 70.95+/-21.65ms (p<0.001). On the other hand, the group without reperfusion showed DeltaQT significant increase - from 81.27+/-20.52ms up to 91.85+/-24.66ms (p<0.001). Logistic regression analysis showed that reduction magnitude between pre- and post-thrombolysis DeltaQT was the independent factor to most effectively identify coronary reperfusion (OR 1.045, p<0.0001; CI 95%). No significant difference was found in dispersion measures when patients with ventricular arrhythmias were compared with those with no arrhythmias in the course of the first 48 hours.nnnCONCLUSIONnThe study shows that DeltaQT is significantly reduced in patients with acute myocardial infarction submitted to successful thrombolysis, and is increased in infarcted patients with closed artery. DeltaQT reduction between the pre- and post-thrombolysis condition was a predictor for coronary reperfusion of those patients, and did not show correlation to ventricular arrhythmias.

Diltiazem as an alternative to beta-blocker in coronary artery computed tomography angiography.

BACKGROUNDnReducing heart rate (HR) in CT angiography of the coronary arteries (CTACor) is critical to image quality. The effectiveness of calcium channel blockers as alternatives for patients with contraindications to beta-blockers has not been established.nnnOBJECTIVESnTo compare the efficacy in the reduction of HR and RR variability of metoprolol and diltiazem in CTACor.nnnMETHODSnProspective, randomized, open study that included patients with clinical indication of CTACor in sinus rhythm with HR > 70 bpm and no use of agents that could interfere with HR. Fifty patients were randomized to the groups: metoprolol IV 5-15 mg or up to HR ≤ 60 bpm (M), and diltiazem IV 0.25 to 0.60 mg/kg or up to HR ≤ 60 bpm (D). Blood pressure (BP) and HR were measured at baseline, 1 minute, 3 minutes and 5 minutes after the agents, at the acquisition and after CTACor.nnnRESULTSnHR reduction in absolute values was higher in group M than in group D (1, 3, 5 min, acquisition and post-test). The percentage reduction of HR was significantly higher in group M only 1 min and 3 min after the start of the agents. There was no difference in 5 min at acquisition and after examination. The percentage RR variability in group D was lower than that in group M during acquisition (RR variability/mean HR of acquisition). A single case of AVB, 2:1 Mobitz I occurred, which was spontaneously reverted (group D).nnnCONCLUSIONnWe conclude that diltiazem is an effective and safe alternative to beta-blockers in the reduction of HR when performing computed tomography angiography of coronary arteries.

CRT-700.06 Safety of Endovascular Therapeutic Hypothermia as an Adjuvant Therapy in Acute ST Segment Elevation Myocardial Infarction

Therapeutic hypothermia (TH) reduces the damage by ischemia and reperfusion cell syndrome in cardiac arrests, in which its application is already widely established and carried out in centers of excellence. However its role in patients with acute ST segment elevation myocardial infarction (STEMI)