Transient giant negative T wave in acute anterior myocardial infarction predicts R wave recovery and preservation of left ventricular function.

OBJECTIVE: To investigate the value of a giant negative T wave (> or = 1.0 mV) in precordial leads of 12-lead electrocardiograms in the acute phase of Q wave myocardial infarction as a predictor of myocardial salvage. METHODS: Coronary angiographic and electrocardiographic findings, left ventricular ejection fraction in the chronic stage, and levels of cardiac enzymes were compared in patients with myocardial infarction with (group GNT, n = 31) and without (group N, n = 20) a giant negative T wave. GNT patients were divided into two subgroups according to the presence (GNT:R[+], n = 10) or absence (GNT: R[-], n = 21) of R wave recovery with an amplitude > or = 0.1 mV in at least one lead that had shown Q waves. RESULTS: The maximum level of creatine kinase and the total creatine kinase were lower in group GNT compared with group N (P < 0.05). The left ventricular ejection fraction was higher in group GNT than in group N (P < 0.05). The maximum creatine kinase and total creatine kinase were lower in GNT:R(+) than in GNT:R(-) (P < 0.01). The left ventricular ejection fraction was higher in GNT:R(+) than in GNT:R(-) (P < 0.01). The frequency of R wave recovery was significantly higher when giant negative T waves appeared within 100 h of myocardial infarction or when the maximum potential was > or = 1.4 mV. The appearance of a giant negative T wave > or = 1.4 mV had a sensitivity of 90%, a specificity of 71.4%, a diagnostic accuracy of 77.4%, a positive predictive value of 60%, and a negative predictive value of 93.8% for prediction of R wave recovery. CONCLUSIONS: The appearance of a giant negative T wave, especially within 100 h of the onset of myocardial infarction, with a maximum potential of > or = 1.4 mV, may predict a reappearance of the R wave and a better left ventricular function in patients in the chronic stage of anterior myocardial infarction.

Spatial ventricular gradient in patients with Wolff-Parkinson-White syndrome in comparison with normal subjects: vectorcardiographic evidence for significant repolarization changes due to preexcitation.

We investigated the use of the spatial ventricular gradient (VG) from vectorcardiogram (VCG) to determine whether significant repolarization differences were present in patients with WPW syndrome compared with normal subjects and also examined which VG parameter (i.e., elevation, azimuth, and magnitude) reflected the differences in repolarization properties during preexcitation. VG was calculated in 49 patients of Wolff-Parkinson-White (WPW) syndrome (group A: left-sided accessory pathway, n = 29; group B: right-sided, n = 20). Group N consisted of 607 normal subjects. In group A, the azimuth of VG was significantly (p < 0.01) greater than in groups B and N. In group B, the elevation of VG was significantly (p < 0.01) greater than in groups A and N. There were no significant differences in the magnitude of VG among groups. QRS duration was significantly (p < 0.01) related with the elevation of VG in group B. These findings suggested that VG is useful for spatial evaluation of repolarization abnormalities during preexcitation, which are related to the site of the accessory pathway.

Evaluation of QRST isointegral maps in detecting posterior myocardial infarction with and without conduction disturbance.

We investigated the usefulness of QRST isointegral maps (I-maps) for detecting posterior myocardial infarction (MI) with and without conduction disturbance. The I-maps were recorded during sinus rhythm and right ventricular (RV) pacing, which simulated left bundle-branch block (LBBB) in 19 patients with and in 20 patients without MI. Data on 608 normal subjects were used as controls. The "-2 SD area," where the QRST integral value was less than the lower limit of the normal range, was assessed by sigma DM (sum of QRST integral values below the normal range). Posterior MI was diagnosed with a sensitivity of 84%, a specificity of 90%, and a diagnostic accuracy of 87%, assuming that MI was present if sigma DM exceeded 50 mVms. During simulated LBBB, when the criterion sigma DM more than 250 mVms was used, the sensitivity, specificity, and diagnostic accuracy were 79, 75, and 77%, respectively. Thus, I-maps may be useful in detecting posterior MI in patients with and without an intraventricular conduction disturbance.

Long-term effects of niceritrol on serum lipoprotein(a) and lipids in patients with high levels of lipoprotein(a).

The long-term effects of niceritrol on lipoprotein(a) (Lp[a]), lipids, apolipoproteins, and fibrinogen and fibrinolytic factors were evaluated in 20 outpatients who had serum Lp(a) levels higher than 20 mg/dL. The mean ( +/- SE) levels of Lp(a) decreased from 33.6 +/- 2.3 mg/dL to 23.5 +/- 3.5 mg/dL after 12 months of niceritrol treatment (P < 0.01). Serum levels of triglycerides and apolipoprotein E decreased significantly and high-density lipoprotein cholesterol (HDL-C) increased significantly after 12 months (P < 0.05). There were no significant changes overall in fibrinogen and fibrinolytic factors, although fibrinogen concentrations showed a tendency to decrease with treatment. PAI-1 levels decreased significantly (P < 0.05) after 6 months of niceritrol treatment. A significant correlation of percent reduction between Lp(a) and apolipoprotein B levels (P < 0.01) was observed, suggesting that the Lp(a)-lowering effects of niceritrol may be due to niceritrol inhibition of apolipoprotein B synthesis, the major apolipoprotein of Lp(a). The ability of niceritrol to decrease Lp(a) levels and increase HDL-C levels, together with its tendency to lower fibrinogen levels, may help prevent coronary events in patients with high levels of Lp(a).

Long-term efficacy of acute thrombolytic therapy for myocardial infarction.

We conducted a retrospective study (1981-1990) to determine whether the efficacy of intracoronary thrombolysis (ICT) could be evaluated from data obtained solely after recanalization. We investigated 55 successful ICT patients (38 with anterior and 17 with inferior myocardial infarction (MI)), and 31 control infarct patients without recanalization. The total serum creatine phosphokinase release (sigma CPK), the extent of infarction measured by T1-201 single photon emission computed tomography (total DS) and the disturbance of regional wall motion (asyn.%) were investigated as parameters for distinguishing the successful ICT and control groups. Discriminatory ability for the two groups was highest with the total DS in all patients. Only the total DS differed significantly between the two groups in patients with inferior infarction. Misidentification of control patients as successful patients was least frequent (25.5%) when using the total DS. These findings suggest that the effectiveness of ICT for acute MI may be assessed on the basis of data obtained solely after recanalization, with the total DS being particularly useful.