A specific combination of P wave duration and morphology accurately predicts the presence of left atrial low voltage area in patients with atrial fibrillation.

BACKGROUND: Since low voltage area (LVA) impairs not only intra atrial conduction velocity but also intra atrial propagate direction, these alternates may reflect the P wave duration (PWD) and morphology. We examined the relationship between the PWD, morphology and LVA. METHODS: Consecutive 127 AF patients were divided into 2 groups depending on the presence of LVA (35 subjects LVA positive group, 92 subjects LVA negative group). P wave morphologies were divided into 3 categories, normal: P-wave duration<120 ms, partial interatrial block (IAB): P wave duration≥120 ms, advanced IAB: PWD ≥ 120 ms with biphasic P waves in inferior leads. LVA was defined as a voltage amplitude<0.5 mV, and qualitatively assessed to be categorized into three grades (mild<10%, 10% ≤ moderate<30%, 30% ≤ extensive). RESULTS: LVA was significantly highly detected in patients of advanced age, female, comorbidities of hypertension, prior brain infarction, LA enlargement. PWD was correlated with LA volume in the LVA negative group, but not in the LVA positive group. Advanced IAB was significantly accumulated in the LVA positive group while partial IAB was found in both LVA positive and negative groups. Receiver-operating characteristics curve revealed that a combination of IAB and biphasic P wave in any inferior lead identified the presence of LVA with 83% sensitivity and 98% specificity. PWD and the presence of advanced IAB were independent predictors of LVA as determined by multivariate logistic regression analysis. CONCLUSION: Advanced IAB is a favorable parameter for the presence of LVA.

Effect of preinfarction angina pectoris on myocardial blush grade after reperfusion in first anterior wall acute myocardial infarction.

BACKGROUND: The aim of the present study was to clarify the effect of preinfarction angina pectoris (PIA) on myocardial blush grade (MBG), a simple marker of myocardial tissue-level reperfusion, in acute myocardial infarction (AMI). METHODS AND RESULTS: One hundred forty-two patients with first anterior wall AMI who were admitted within 6 h after onset of symptoms were examined. PIA was defined as typical chest pain within 48 h before onset of symptoms. MBG was evaluated by coronary angiography after reperfusion. Patients with MBG 2 or 3 (n=103) had a higher frequency of PIA and a lower frequency of diabetes mellitus than those with MBG 0 or 1 (n=39) (57% vs 28%, p=0.004, and 23% vs 44%, p=0.03, respectively). The former had a lower peak creatine kinase level and a greater left ventricular ejection fraction at predischarge than the latter (3,652+/-2,440 vs 5,507+/-3,058 IU/L, p=0.0002, and 57+/-12% vs 45+/-11%, p<0.0001, respectively). Multivariate logistic regression analysis showed that PIA (p=0.004) and diabetes mellitus (p=0.03) were independently associated with MBG 2 or 3 after reperfusion. CONCLUSIONS: PIA has beneficial effects on myocardial tissue-level reperfusion evaluated by MBG in first anterior wall AMI.

Circadian variation in symptomatic subacute stent thrombosis after bare metal coronary stent implantation.

The present study examined whether onset of symptomatic subacute stent thrombosis (SAT) varies in a circadian manner after bare metal coronary stent implantation. Among 2,305 patients who underwent bare metal coronary stent implantation, 21 (0.9%) developed symptomatic SAT. Results of the present study indicate that onset of symptomatic SAT is more frequent between 6:00 A.M. and 12:00 P.M. than at any other measured 6-hour period during the day.

Significance of neutrophil counts after reperfusion therapy in patients with a first anterior wall acute myocardial infarction.

BACKGROUND: Previous studies have demonstrated that an elevated neutrophil count on admission is associated with a higher risk of adverse events after acute myocardial infarction (AMI). However, the significance of the neutrophil count after reperfusion therapy has not been elucidated. METHODS AND RESULTS: The association of the neutrophil count on admission and days 2 and 3 with peak creatine kinase (CK) concentration, ST-segment resolution (a marker of myocardial tissue-level reperfusion), and left ventricular (LV) function at predischarge were examined in 122 patients (102 men, 20 women, mean age 61+/-11 years) with a first anterior wall AMI. Neutrophil counts were increased on day 2 and decreased on day 3 compared with admission (8,768+/-3,005 mm3, 6,617+/-2,424 mm3, and 7,725+/-3,388 mm3, respectively). Patients with ST-segment resolution (n=52) had lower neutrophil counts on days 2 and 3 than those without it (n=70), but neutrophil counts on admission did not differ significantly between patients with and without ST-segment resolution. Neutrophil counts on admission and days 2 and 3 were weakly but significantly correlated with peak CK concentration (r=0.31, p=0.0004; r=0.43, p<0.0001; r=0.32, p=0.003, respectively) and with LV ejection fraction at predischarge (r=-0.18, p=0.04; r=-0.26, p=0.003; r=-0.27, p=0.003; respectively). CONCLUSION: The neutrophil count after reperfusion is weakly but significantly correlated with infarct size, myocardial tissue-level reperfusion, and LV function at predischarge in a first anterior wall AMI. These correlations were slightly stronger than the correlations with the neutrophil count on admission.