Yo Nagahama

Atrial fibrillation in inferior wall Q-wave acute myocardial infarction.

Abstract Although atrial fibrillation (AF) is a relatively common arrhythmia occurring during the course of acute myocardial infarction (AMI), the mechanisms involved in its genesis remain controversial and are mostly focused on the left ventricle and atrium: left ventricular failure, pericarditis and left atrial ischemia.1–4 In contrast, the role of hemodynamic change imposed on the right ventricle and right atrium related to the onset of AF after AMI is poorly understood. Because hemodynamic change of the right ventricle is often observed in inferior AMI, we hypothesized that hemodynamic impairment, audible pericardial friction rub, electrocardiographic evidence of right ventricular AMI and age may be important clinical factors associated with the occurrence of AF. In this study, multivariate analysis was used to assess the clinical settings associated with the occurrence of AF in patients with their first Q-wave inferior AMI.

Left ventricular free wall rupture after reperfusion therapy for acute myocardial infarction.

We evaluated the clinical significance of angiographic indexes and pericardial involvement in predicting increased risk of free wall rupture after reperfusion therapy and found that Thrombolysis In Myocardial Infarction (TIMI) <3 flow grade after reperfusion therapy was a significant variable related to the free wall rupture. Moreover, pericardial rub was found to be a significant variable related to TIMI <3 grade flow after reperfusion, which indicates that detection of pericardial rub is one of the clinical signs that predicts inadequate anterograde flow of the infarct-related artery after reperfusion and hence, higher risk for free wall rupture.

PQ Segment Depression in Acute Q Wave Inferior Wall Myocardial Infarction

BACKGROUND PQ segment deviation is almost as characteristic as the classic ST segment deviation and is detected in most patients with pericarditis. However, as infarction-associated pericarditis remains over the infarct zone, PQ segment depression is observed much less often in patients with acute myocardial infarction. METHODS AND RESULTS We designed this study to examine the clinical significance of PQ segment depression in acute Q wave inferior myocardial infarction. We examined 171 consecutive patients with acute Q wave inferior myocardial infarction by means of auscultation, ECG, and two-dimensional echocardiography. The diagnosis of pericarditis was made on the basis of pericardial rub detected by more than two observers during the first 3 days after admission. At least 0.5 mm of PQ segment depression from the TP segment lasting more than 24 hours in both limb and precordial leads was considered diagnostic of PQ segment depression. CONCLUSIONS PQ segment depression was present in 14 patients and absent in 157 patients. Eleven patients with and 55 patients without PQ segment depression had advanced asynergy (akinesis or dyskinesis) in the posterior segments, whereas 9 patients with and 20 patients without PQ segment depression had pericardial rub. When multivariate analysis was performed to determine the important variables related to the occurrence of PQ segment depression, pericardial rub was selected with advanced asynergy of the posterior segment as significant factors related to PQ segment depression. Major complications (ventricular fibrillation, sustained ventricular tachycardia, cardiogenic shock, need for pacing) were present in 63 patients; 9 with (64%) and 54 without (34%) PQ segment depression. PQ segment depression was one of the clinical signs of more extensive damage extending to the posterior segments and increased incidence of major complications.

Clinical significance of PQ segment depression in acute Q wave anterior wall myocardial infarction

OBJECTIVES This study was designed to evaluate the clinical significance of PQ segment depression and to examine the frequency of PQ segment depression in infarction-associated pericarditis. BACKGROUND PQ segment deviation is almost as characteristic as the classic ST segment deviation and is detected in most patients with pericarditis. However, the incidence and clinical characteristics of PQ segment depression in acute myocardial infarction are not defined. METHODS Three hundred four consecutive patients with acute Q wave anterior wall myocardial infarction were examined carefully by auscultation, electrocardiogram, echocardiogram and chest roentgenogram. The diagnosis of pericarditis was made on the basis of pericardial rub detected by more than two observers during the 1st 3 days after hospital admission. At least 0.5 mm of PQ segment depression from the TP segment observed for > 24 h in both limb and precordial leads was considered diagnostic of PQ segment depression. RESULTS A pericardial rub was present in 65 patients (21%) and absent in 239 patients. PQ segment depression was detected in both limb and precordial leads in 30 patients (10%): 18 patients with pericardial rub and 12 patients without pericardial rub. On the basis of five clinical variables, multivariate analysis was performed to determine the important variables related to the occurrence of PQ segment depression. Pericardial rub was selected with left ventricular segments with advanced asynergy as a significant factor related to PQ segment depression. There were 31 in-hospital deaths, and a significantly higher hospital mortality rate was observed in patients with PQ segment depression (23% vs. 9%). CONCLUSIONS Although PQ segment depression was observed in a minority of patients with infarction-associated pericarditis, it was one of the clinical signs of larger infarct size and increased hospital deaths.

Precordial ST segment depression in patients with Q wave inferior myocardial infarction : role of infarction-associated pericarditis

To examine the diagnostic significance of precordial ST segment depression in Q wave inferior myocardial infarction, 157 consecutive patients were examined carefully by means of auscultation, ECG, and two-dimensional echocardiography. Precordial ST segment depression was transient (lasting < 72 hours from the onset of myocardial infarction) in 63 patients and persistent (> or = 72 hours) in 40. Twenty-eight patients with persistent, 19 patients with transient, and 14 patients without precordial ST segment depression had advanced asynergy (akinesia or dyskinesia) in the posterior segments, whereas 13 patients with persistent, six with transient, and six without precordial ST segment depression had pericardial rub. Patients with persistent precordial ST segment depression had a significantly higher incidence of severe wall motion abnormality (p < 0.01) and inflammation (p < 0.05) of the posterior wall than the other two groups. In 5 of 40 patients with persistent ST segment depression, pericardial rub was detected in the absence of advanced asynergy in the posterior segments. Although not highly sensitive, persistent precordial ST segment depression appeared to be a fairly specific indicator (specificity 92%) of concomitant posterior involvement with severe wall motion abnormality, inflammation, or both.

Residual left ventricular pump function following acute myocardial infarction in postmenopausal diabetic women

BackgroundThe Framingham Study indicated that women with diabetes mellitus developed cardiac failure four times more often than those without diabetes mellitus after acute myocardial infarction. However, there is little information on residual left ventricular pump function after myocardial infarction in female diabetic patients. MethodsTo evaluate the difference between postmenopausal women and age-matched men in the impact of diabetes mellitus on left ventricular pump function during the first year after myocardial infarction, radionuclide angiography was performed during the third week after acute myocardial infarction and again 1 year later in 50 patients (21 women, 29 men) with diabetes mellitus and 62 patients (25 women, 37 men) without diabetes mellitus. ResultsAlthough the radionuclide angiographie indices did not change during the first year after myocardial infarction in non-diabetic patients, left ventricular end-diastolic volume increased, and the left ventricular ejection fraction, the regional ejection fraction of the non-infarcted area, and the ratio of arterial systolic blood pressure to left ventncular end-systolic volume (pressure:volume ratio) decreased in the diabetic patients. Furthermore, the degree of change in the left ventricular end-diastolic volume, the left ventricular ejection fraction, the regional ejection fraction of the non-infarcted area, and the pressure: volume ratio in diabetic women was larger than that in diabetic men. ConclusionThe increase in the left ventricular end-diastolic volume and the decrease in the regional ejection fraction of the non-infarcted area during the first year after myocardial infarction in postmenopausal women with diabetes mellitus indicate that female sex associated with diabetes mellitus may be important factors in left ventricular remodeling in postmenopausal women.

Clinical significance of pericardial effusion in Q-wave inferior wall acute myocardial infarction.

To assess the clinical significance of pericardial effusion in Q-wave inferior wall acute myocardial infarction, 185 consecutive patients were examined by means of electrocardiogram, echocardiogram and hemodynamic monitoring. A pericardial effusion was present in 44 patients and was absent in 141 patients. Electrocardiographic right ventricular infarction (> or = 1 mm of ST-segment elevation and Q wave in V4R) was detected in 54 patients, with 20 patients having pericardial effusion. Patients with pericardial effusion had significantly more left ventricular segments with advanced asynergy, lower cardiac output, higher pulmonary artery wedge pressure and higher incidence of right ventricular infarction than those without pericardial effusion. There were 17 in-hospital deaths. Although there was no significant difference in the mortality rate between patients with and without right ventricular infarction, a significantly higher hospital mortality rate was observed in patients with pericardial effusion compared to those without it (23 vs 5%). Pericardial effusion was selected with age and pulmonary artery wedge pressure as important variables associated with hospital mortality by the discriminant analysis. Patients who developed pericardial effusion, regardless of right ventricular infarction, had more extensive myocardial damage, and hence, pericardial effusion was one of the predictors of increased hospital mortality.

Clinical significance of right ventricular dilatation in patients with right ventricular infarction.

BackgroundRight ventricular infarction can be accurately diagnosed by ST-segment elevation in the right precordial leads. However, the clinical outcome of right ventricular infarction encompasses a wide spectrum, ranging from no hemodynamic compromise to cardiogenic shock. The present study examined the clinical significance of echocardiographic right ventricular dilatation in patients with right ventricular infarction. MethodsWe studied 60 consecutive patients with ECG evidence of right ventricular infarction (at least 1 mm ST-segment elevation and QS or QR in V4R) after their first acute Q-wave inferior infarction. They had been admitted to the coronary care unit within 24 h of the onset of chest pain. The presence of right ventricular dilatation was diagnosed when the end-diastolic ratio between right and left ventricle was more than 0.5 on two-dimensional echocardiogram. ResultsOf the 60 patients with ECG evidence of right ventricular infarction, 29 had right ventricular dilatation (group 1) and 31 did not (group 2). We used four clinical variables in multivariate analysis to determine the significant factors related to right ventricular infarction. Mean right atrial pressure and number of left ventricular segments with advanced asynergy were found to be the important factors. Furthermore, a significantly higher incidence of major complications (cardiogenic shock and need for temporary pacing) was observed in group 1 than in group 2. Right ventricular dilatation was found to be the significant factor related to major complications. ConclusionEchocardiographic right ventricular dilatation is an important non-invasive sign obtained on admission in patients with right ventricular infarction, because it is associated with larger left ventricular infarct size and increased risk of major complications.

Cardiovascular response to combined static-dynamic exercise of patients with myocardial infarction.

BackgroundGraded dynamic exercise‐stress testing of patients with acute myocardial infarction prior to discharge from hospital has an important diagnostic and prognostic implication. Although many daily tasks involve combinations of static and dynamic exercise, little is known about cardiovascular responses during combined static–dynamic exercise. ObjectiveTo determine the difference between cardiovascular responses during two types of combined static–dynamic exercise (a 10 kg weight in one hand, and a 10 kg weight bearing on the shoulder). MethodsWe studied 27 male patients who had recently suffered myocardial infarction using ear densitography. The patients were divided into two groups : group 1 was comprised of 14 patients with resting left ventricular end‐diastolic volumes ≥140 ml, and group 2 was comprised of 13 patients with left ventricular end‐diastolic volumes <140 ml. ResultsFor eight patients in group 1 we detected positive electrocardiographic changes during one‐hand weight‐carrying exercise, but for none of these patients was there an electrocardiographic change during weight‐bearing exercise. All the patients in group 2 completed both types of exercise without significant ST‐segment change. Although there were no significant differences between values of any of the indices measured for the two groups during weight‐bearing exercise, patients in group 1 had significantly shorter diastolic times/min (21.8±2.1 versus 25.1±2.4 s/min, P  < 0.01) during one‐hand weight carrying. ConclusionsIn addition to decrease in subendocardial coronary blood flow associated with increase in left ventricular end‐diastolic volume, shortening of diastolic perfusion time during one‐hand weight‐carrying exercise for patients in group 1 can potentially contribute to subendocardial ischemia, which was favorably altered by bearing a weight on the shoulder.

Clinical significance of pericardial rub in inferior wall Q-wave acute myocardial infarction

Pericardial rub is common during the course of acute myocardial infarction (AMI).1–3 Infarct-associated pericardial rub is usually transient and associated with transmural AMI,1,3 but it has been reported with a greatly variable frequency and its incidence in respect to the infarct site is controversial.1–3 Some have observed that pericardial rub was a more frequent complication in anterior rather than inferior infarcts.2,3 Others1 report that pericardial rub was equally distributed among patients with anterior and inferior AMI. Because the proximity of the stethoscope to the inflamed pericardium permits better detection of rubs, we hypothesized that the association of right ventricular AMI could affect the incidence of pericardial rub in patients with inferior AMI. We elucidated the difference in the incidence of pericardial rub with and without right ventricular AMI in patients after their first Q-wave inferior AMI.