Konomi Sakata

Clinical and Prognostic Significance of Atrial Fibrillation in Acute Myocardial Infarction

The clinical significance of the time of onset of atrial fibrillation (AF) was investigated in patients with acute myocardial infarction (AMI). Among 1,039 patients with AMI, 100 (9.6%) had AF. These patients were divided into 3 groups: AF group 1 (n = 45), who developed AF within 24 hours of the onset of AMI; AF group 2 (n = 41), who developed AF >24 hours after the onset of AMI; and AF group 3 (n = 14), who developed AF before the onset of AMI. The infarct-related lesion was most frequent (67%) in the proximal right coronary artery in AF group 1 (p <0.01). Right atrial pressure was most significantly increased in AF group 1. The left atrial dimension and pulmonary arterial wedge pressure were most significantly increased, and left ventricular ejection fraction was most significantly decreased in AF group 2. In the acute phase, the frequencies of heart failure, cardiogenic shock, and in-hospital mortality were higher for all 3 AF groups than the sinus group (p <0.01). The long-term survival rate was significantly lower in AF group 1 and AF group 2 than in the sinus group. AF was an independent predictor of cardiac death in both AF group 1 (odds ratio 2.5; 95% confidence interval 1.2 to 5.0; p = 0.0012) and AF group 2 (odds ratio 3.7; 95% confidence interval 1.8 to 7.5; p = 0.0005), but not in AF group 3. The onset time of AF appears to be a useful parameter for evaluating the cardiac status and prognosis of patients with AMI.

Relation of ST-Segment Changes in Inferior Leads During Anterior Wall Acute Myocardial Infarction to Length and Occlusion Site of the Left Anterior Descending Coronary Artery

We investigated the relation between left anterior descending (LAD) coronary artery morphology and inferior lead ST-segment changes to elucidate the clinical significance of such changes in 159 patients with anterior wall acute myocardial infarction (AMI). Patients with 1-vessel LAD artery lesions were divided into an ST depression group (n = 40), an ST elevation group (n = 25), and a no-ST-change group (n = 94) based on ST-segment changes in the inferior leads. The relation between each group and the infarct-related lesion and the presence of a wrapped LAD artery was then investigated. The percentage of patients with the infarct-related lesion in the proximal LAD artery was significantly higher in the ST depression group and significantly lower in the ST elevation group. The percentage of patients with a wrapped LAD artery was significantly higher in the ST elevation group and significantly lower in the ST depression group. The wall motion index determined echocardiographically was significantly higher in the ST depression group and the no-ST-change group than in the ST elevation group. Our findings suggest that inferior lead ST-segment changes during anterior wall AMI arise as a result of competition between reciprocal changes caused by high lateral wall AMI due to lesions of the proximal LAD artery, which depress the ST segment, and inferoapical wall AMI due to a wrapped LAD artery, which elevates the ST segment. In patients with no ST-segment changes, echocardiography was useful for distinguishing the amount of affected LAD artery territory.

Sequential changes in cardiac structure and function in patients with Duchenne type muscular dystrophy : A two-dimensional echocardiographic study

BACKGROUND Most patients with progressive muscular dystrophy of the Duchenne type (DMD) die of respiratory failure at approximately 20 years of age. However, some patients with DMD die of heart failure in relatively short periods of time. We investigated the long-term progression of cardiac impairment in patients with DMD by two-dimensional echocardiography. METHODS We monitored 74 patients for 4 years with two-dimensional echocardiography. Patients were classified into four groups according to the 8-grade Swinyard-Dever system. We also evaluated the echocardiographic features of 22 other patients with DMD with studies performed within 1 year before their deaths. RESULTS During the 4-year follow-up the left ventricle expanded, and regional left ventricular wall motion abnormalities developed in the posterior wall and apex. Almost all patients had myocardial dysfunction that progressed in parallel with their Swinyard-Dever stage. However, in a few patients who died of congestive heart failure, left ventricular dilation and circumferential left ventricular wall motion were severely impaired. CONCLUSIONS Myocardial impairment is accelerated in patients with DMD who died of heart failure. Two-dimensional echocardiography is a useful tool for the early diagnosis of left ventricular dysfunction and provides useful information for the treatment of patients with DMD.

Normal values and clinical relevance of left atrial myocardial function analysed by speckle-tracking echocardiography: multicentre study

AIMS The aim of this multicentre study was to determine the normal range and the clinical relevance of the myocardial function of the left atrium (LA) analysed by 2D speckle-tracking echocardiography (2DSTE). METHODS AND RESULTS We analysed 329 healthy adult subjects prospectively included in 10 centres and a validation group of 377 patients with left ventricular diastolic dysfunction (LVDD). LA myocardial function was analysed by LA strain rate peak during LA contraction (LA-SRa) and LA strain peak during LA relaxation (LA-Strain). The range of values of LA myocardial function in healthy subjects was LA-SRa -2.11 ± 0.61 s(-1) and LA-Strain 45.5 ± 11.4%, and the lowest expected values of these LA analyses (calculated as -1.96 SD from the mean of healthy subjects) were LA-SRa -0.91 s(-1) and LA-Strain 23.1%. Concerning the clinical relevance of these LA myocardial analyses, LA-SRa and LA-Strain detected subtle LA dysfunction in patients with LVDD, even though LA volumetric measurements were normal. In addition, in these patients we found that the functional class (dyspnoea-NYHA classification) was inversely related to both LA-Strain and LA-SRa. CONCLUSION In the present multicentre study analysing a large cohort of healthy subjects and patients with LVDD, the normal range and the clinical relevance of the myocardial function of the LA using 2DSTE have been determined.

Usefulness of P-Wave Dispersion in Standard Twelve-Lead Electrocardiography to Predict Transition from Paroxysmal to Persistent Atrial Fibrillation

A prospective study was conducted to investigate the validity of the hypothesis that P-wave dispersion (Pd) may be a clinically useful predictor of progression from paroxysmal to persistent atrial fibrillation (AF). Two hundred four consecutive patients with a diagnosis of paroxysmal AF were studied. Standard 12-lead electrocardiography and echocardiography were performed on all patients at the time of entry into the study. Pd was measured as the difference between maximum and minimum P-wave duration in any of the 12 leads. Mean follow-up was 66 +/- 8 months. Group I included patients (n = 132) in whom paroxysmal AF did not progress to persistent AF, and group II included those (n = 72) who developed persistent AF. In group II, age, percentage of men, percentage of patients with diabetes mellitus, maximum P-wave duration, Pd, and left atrial dimension were significantly higher than in group I (p <0.05). Multivariate logistic regression analysis using these 6 factors identified age (odds ratio 2.18, 95% confidence interval 1.41 to 3.41, p <0.01) and Pd (odds ratio 1.91, 95% confidence interval 1.51 to 2.44, p <0.01) as independent predictors of a transition to persistent AF. Pd >or=40 ms predicted progression to persistent AF with sensitivity of 71%, specificity of 77%, positive predictive value of 63%, negative predictive value of 83%, and accuracy of 75%. In conclusion, Pd was a clinically useful predictor of progression from paroxysmal to persistent AF.

Characterization of predictors of in-hospital cardiac complications of takotsubo cardiomyopathy: Multi-center registry from Tokyo CCU Network

BACKGROUND Takotsubo cardiomyopathy (TC) is an acute cardiac syndrome characterized by transient left ventricular dysfunction and relatively good prognosis after discharge. However, cardiac complications during hospitalization remain to be fully determined. We attempted to determine features characterizing patients with adverse clinical outcome by comparing those with cardiac complication and without cardiac complication during hospitalization. METHODS AND RESULTS We investigated 107 patients with TC from the Tokyo CCU Network database, comprising 67 cardiovascular centers in the metropolitan area during January 1 to December 31, 2010. Cardiac complications were defined as cardiac death, pump failure (Killip grade≥II), sustained ventricular tachycardia or fibrillation (SVT/VF), and advanced atrioventricular block (AVB). Cardiac complications were observed in 41 patients (37 pump failure complicated by 3 cardiac deaths and 2 SVT/VF and 2 AVB without pump failure), and there was no cardiac complication in the remaining 66 patients. There was no difference in age, peak creatinine kinase level, C-reactive protein level and ST elevation on electrocardiogram. Multiple logistic regression analysis showed that white blood cell count (p=0.039) and brain natriuretic peptide (p=0.001) were independent predictors of in-hospital adverse cardiac complications. CONCLUSIONS Cardiac complications are relatively high in patients with TC during hospitalization. High white blood cell count and brain natriuretic peptide level are associated with poor clinical outcome in patients with TC.

Prognostic value of Doppler transmitral flow velocity patterns in acute myocardial infarction.

Doppler transmitral flow patterns are partially dependent on age. We investigated the correlations between the age-adjusted transmitral flow patterns, hemodynamic indexes, and the coronary and clinical outcome in 206 patients with acute myocardial infarction (AMI) and 102 normal control subjects. The peak flow velocity at atrial contraction was significantly lower in 50 of the 206 patients (24%) (low-A group) than in the 102 normal controls. Pulmonary capillary wedge pressure was significantly higher in the low-A group than in the remaining 156 patients with AMI (20 +/- 7 vs 11 +/- 5 mm Hg, p <0.001), and the cardiac index and left ventricular ejection fraction were significantly lower (2.2 +/- 0.6 vs 2.9 +/- 0.7 L/min/m2, p <0.001; 38 +/- 15% vs 52 +/- 13%, p <0.001). The incidence of cardiogenic shock was significantly higher in the low-A group than in the other patients with AMI (42% vs 19%, p <0.001). Regression analysis demonstrated a significant association between decreased atrial filling velocity and increased in-hospital mortality as well as the incidence of heart failure in AMI (p <0.001). The 5-year mortality rate was also significantly higher in the low-A group (p <0.001). The age-adjusted transmitral flow pattern in AMI can identify patients with left ventricular dysfunction, which can lead to a poor prognosis.

Prognostic significance of persistent right ventricular dysfunction as assessed by radionuclide angiocardiography in patients with inferior wall acute myocardial infarction.

We evaluated cardiac hemodynamics and long-term prognosis in patients with right ventricular (RV) acute myocardial infarction (AMI) using Fourier phase and amplitude analysis of radionuclide angiocardiographic scanning. In 143 patients with RV AMI, delayed phase and low amplitude in radionuclide RV images persisted in 54 patients (persistent RV dysfunction group) 3 months after AMI, but disappeared in the remaining 89 patients (improved RV function group). No significant differences were present in RV dimensions, left ventricular (LV) wall motion, LV ejection fraction, or RV ejection fraction between these groups during the acute phase. At 3 months, RV dimension and LV and RV wall motion indexes were significantly higher (p = 0.0292, p = 0.0124, p<0.0001, respectively), and LV and RV ejection fractions were lower (p = 0. 0174 and p = 0.0008, respectively) in the persistent RV dysfunction group. Percutaneous transluminal coronary angioplasty in the acute phase was performed in a smaller group of patients (15% vs. 34%, p = 0.0223), and the degree of residual stenosis in the proximal right coronary artery was significantly greater in the persistent RV dysfunction group than in the improved RV function group (82+/-22% vs. 53+/-30%, p<0.0001). The 8-year survival rate was significantly lower in the persistent RV dysfunction group (p<0.0001). Persistent abnormality of phase and amplitude in radionuclide RV images was a significant independent predictor of long-term survival (odds ratio 10.42; 95% confidence interval 3.65 to 29.71; p<0.0001). Radionuclide angiocardiographic Fourier phase and amplitude scanning can detect persistent RV dysfunction in patients with RV AMI and can predict patient outcome.

Multidirectional Global Left Ventricular Systolic Function in Normal Subjects and Patients with Hypertension: Multicenter Evaluation

BACKGROUND The aim of this multicenter study was to determine the normal ranges and the clinical relevance of multidirectional systolic parameters to evaluate global left ventricular (LV) systolic function. METHODS Three hundred twenty-three healthy adult subjects prospectively included at 10 centers and a cohort of 310 patients with hypertension were analyzed. Multidirectional global LV systolic function was analyzed using two-dimensional speckle-tracking echocardiography by means of two indices: longitudinal-circumferential systolic index (the average of longitudinal and circumferential global systolic strain) and global systolic index (the average of longitudinal, circumferential, and radial global systolic strain). RESULTS The ranges of values of the multidirectional systolic parameters in healthy subjects were -21.22 ± 2.22% for longitudinal-circumferential systolic index and 29.71 ± 5.28% for global systolic index. In addition, the lowest expected values of these multidirectional indices were determined in this population (calculated as -1.96 SDs from the mean): -16.86% for longitudinal-circumferential systolic index and 19.36% for global systolic index. Concerning the clinical relevance of these measurements, these indices indicated the presence of subtle LV global systolic dysfunction in patients with hypertension, even though LV global longitudinal systolic strain and LV ejection fraction were normal. Moreover, in these patients, functional class (dyspnea [New York Heart Association classification]) was inversely related to both the longitudinal-circumferential index and the global systolic index. CONCLUSIONS In the present multicenter study analyzing a large cohort of healthy subjects and patients with hypertension, the normal range and the clinical relevance of multidirectional systolic parameters to evaluate global LV systolic function have been determined.

Myocardial damage and left ventricular dysfunction in patients with and without persistent negative T waves after Q-wave anterior myocardial infarction.

Persistent T-wave inversions during the chronic stage of Q-wave myocardial infarction (MI) indicate the presence of a transmural infarction with a fibrotic layer pathologically. The aim of the present study was to examine the relation between left ventricular (LV) damage and changes in polarity of the T waves from the acute to chronic phase in patients with Q-wave anterior wall MI. We studied 140 patients with persistent T-wave inversions in leads with Q waves (negative T-wave group) and 158 patients with positive T waves (positive T-wave group) at 12 months after anterior MI. In the positive T-wave group, the precordial T waves reverted from a negative to a positive morphology < 3 months after MI in 21 patients (3 M-positive T-wave subgroup), 3 to 6 months in 52 patients (6 M-positive T-wave subgroup), and 6 to 12 months in 75 patients (12 M-positive T-wave subgroup). Ten patients had persistent positive T waves without initial T-wave inversion (persistent positive T-wave group). Wall motion index and LV dimension were higher and the wall thickness for the infarct area and LV ejection fraction were lower in the negative T-wave than in the positive T-wave groups, except the persistent positive T-wave group in the chronic stage (p < 0.0001). Wall motion in the infarcted area improved over the course of 1 year in the 3 M-, 6 M-, and 12 M-positive T-wave subgroups (p < 0.0001), but not in the persistent positive T-wave group. Among the patients with T-wave inversions after admission, those who had persistent negative T waves after 12 months had worse LV function. In patients with initial T-wave inversion, earlier normalization of the precordial T waves was associated with greater improvement in LV function. Patients with persistent positive T waves without initial negative T waves had poorer recovery of LV function than patients with persistent negative T waves. We conclude that the presence of inverted T waves in leads with abnormal Q waves 12 months after MI and the time required for T-wave normalization can be used to assess the degree of LV dysfunction.