Masatsugu Iwase

Early detection of successful coronary reperfusion based on serum myoglobin concentration: Comparison with serum creatine kinase isoenzyme MB activity

The usefulness of serum myoglobin (Mb) concentration for early detection of successful reperfusion was compared with that of creatine kinase isoenzyme MB (CKMB) activity in 49 patients with acute myocardial infarction. To determine accurately the time of reperfusion, we performed coronary angiography every 5 minutes during reperfusion therapy. Reperfusion was obtained in 32 patients (reperfused group) but not in 17 patients (nonreperfused group) until 60 minutes after the initiation of reperfusion therapy. Blood samples were taken before and 15, 30, and 60 minutes after the angiographic confirmation of reperfusion in the reperfused group. In the nonreperfused group, samples were taken before and 15, 30, and 60 minutes after the initiation of treatment. We calculated the Mb ratio (value after reperfusion or treatment initiation to value before) and CKMB ratio (value after to value before). When values > 2.4 for the Mb ratio or > 2.0 for the CKMB ratio were used as the criteria for reperfusion within 60 minutes after initiation of treatment, the sensitivities were 91% and 56% at 15 minutes after reperfusion, 97% and 84% at 30 minutes, and 100% and 100% at 60 minutes, respectively. For each ratio the specificity of detection was 100% at all times evaluated. Thus the Mb ratio accurately detected the success of reperfusion as early as 15 minutes after reperfusion and may be more useful than the CKMB ratio for detecting the success of reperfusion within 30 minutes.

Early detection of successful coronary reperfusion based on serum concentration of human heart-type cytoplasmic fatty acid-binding protein

Both human heart-type cytoplasmic fatty acid-binding protein (H-FABPc) and myoglobin are low molecular weight proteins that are abundant in the cytoplasm of myocardial cells. Unlike myoglobin, H-FABPc content in the skeletal muscle is less than in cardiac muscle. To investigate the usefulness of the serum concentration of H-FABPc in the early detection of successful coronary reperfusion, we measured serum concentrations of H-FABPc and myoglobin in 45 patients with acute myocardial infarction treated with intracoronary thrombolysis or direct percutaneous transluminal coronary angioplasty. Coronary angiography was performed every 5 min for reperfusion therapy to identify the onset of reperfusion. Reperfusion, defined as a TIMI grade 2 or 3, was achieved within 60 min of the initiation of reperfusion therapy in 30 patients (the reperfused group), but was not achieved in 15 patients (the non-reperfused group). Blood samples were obtained before initiation of treatment and 15, 30 and 60 min after initiation of treatment in the non-reperfused group. In the reperfused group, samples were obtained before reperfusion and 15, 30 and 60 min after reperfusion. The H-FABPc ratio (the ratio of value after to value before the initiation of treatment or reperfusion) increased sharply after the onset of reperfusion, peaking at 41 +/- 18 min, and decreased rapidly thereafter. The predictive accuracy of an H-FABPc ratio of > 1.8 for the detection of reperfusion within 60 min of the initiation of treatment was 93% at 15 min after reperfusion, 98% at 30 min, and 100% at 60 min. Similar rates of predictive accuracy were observed for a myoglobin ratio > 2.4. The H-FABPc ratio detected successful reperfusion as early as 15 min after the onset of reperfusion and was highly accurate in detecting reperfusion within 60 min of the onset of reperfusion. The predictive accuracy of the H-FABPc ratio was similar to that of the myoglobin ratio for the early detection of successful coronary reperfusion.

Prognostic value of left atrial volume index in patents with first acute myocardial infarction

AIMS We evaluated the usefulness of left atrial volume index (LAVI) and the degree of changes in LAVI (delta LAVI) during hospitalization for the prediction of prognosis after acute myocardial infarction (AMI). METHODS AND RESULTS We investigated 205 consecutive patients with first AMI. They underwent echocardiography on admission as well as at discharge. Delta LAVI was calculated by subtracting the value on admission from that at discharge. The primary endpoints were major cardiac events (MACE): cardiac death due to heart failure and heart failure hospitalization. During a mean follow-up of 26 months, MACE occurred in 29 patients. Patients were divided into two groups according to the optimal cut-off values of LAVI (32.0 mL/m(2)) at discharge and delta LAVI (2.5 mL/m(2)) derived from receiver operating characteristic curves, respectively; Group I: LAVI ≤ 32.0 mL/m(2), Group II: LAVI > 32.0 mL/m(2) and Group A: delta LAVI ≤ 2.5 mL/m(2), Group B: delta LAVI > 2.5 mL/m(2). In comparisons of two groups, respectively, the incidence of MACE between the groups showed significant differences [Group I (3.8%) vs. Group II (32.0%): P < 0.001, log-rank, Group A (7.4%) vs. Group B (20.0%): P = 0.0079, log-rank]. In multivariate analysis, LAVI at discharge [risk ratio (RR): 1.077, 95% CI: 1.035-1.124, P = 0.0002] and delta LAVI (RR: 1.056, 95% CI: 1.012-1.108, P = 0.0109) were significant. LAVI > 32.0 mL/m(2) at discharge (sensitivity: 93%, specificity: 69%) and delta LAVI > 2.5 mL/m(2) (sensitivity: 79%, specificity: 50%) were predictors of MACE. CONCLUSION LAVI at discharge and delta LAVI would be useful predictors for MACE after first AMI.

The discrepancy between echocardiography, cineventriculography and thermodilution. Evaluation of left ventricular volume and ejection fraction.

We have often experienced disagreement in left ventricular end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF) between cineventriculography and echocardiography not performed simultaneously, and unnaturally hyperdynamic left ventricular wall motion. We determined EDV, ESV, stroke volume, and EF (with modified Simpsons rule) in 65 consecutive patients using 2-dimensional echocardiography with a 2.5 MHz, 128-element phased-array transducer within three days of cardiac catheterization and compared our results with those obtained by the thermodilution technique and biplane cineventriculography. Heart rate and stroke volume were significantly different among the three techniques: cineventriculography yielded the highest values. These findings suggest that patients may have been in a hyperadrenergic state caused by anxiety experienced during invasive cineventriculography and thermodilution examinations. Inter- and intraobserver variabilities for echocardiography differed little from the variability in cineventriculography. Although there were good correlations between echocardiographic and cineventriculographic findings for EDV (r=0.67), ESV (r=0.80), and EF (r=0.78) by two independent observers, there was a lack of agreement for EDV, ESV, and EF. Echocardiographic EDV values were significantly lower than cineventriculographic values. When left ventricular function is good, the left ventricle tends to be hyperadrenergic and in a more hyperdynamic state with smaller ESV than echocardiographic values during cineventriculography. When left ventricular function is poor, the left ventricle tends to be influenced by the effect of the contrast medium and stress during the invasive examinations and in a more hypodynamic state with larger ESV than echocardiographic values during cineventriculography. The echocardiography is highly reproducible and may provide information that is not available from cineventriculography and thermodilution. Cineventriculography may provide another manifestation of cardiac reserve. In conclusion, we must take into account each peculiar property of the echocardiography, the cineventriculography, or the thermodilution technique when patients are examined with cardiac conditions by different methods at different days.

Two cases with past Kawasaki disease developing acute myocardial infarction in their thirties, despite being regarded as at low risk for coronary events

Two patients after Kawasaki disease (KD) developed acute myocardial infarction in their thirties, though coronary artery follow-up were deemed unnecessary because of apparently angiographic normal coronary arteries in their children more than 1-year after acute KD. Angiographic findings of apparently normal coronary arteries in the late period after acute KD are possible to mislead their prognoses. It should be recognized that coronary aneurysms can often regress in the late period. There is ongoing controversy about the therapeutic strategy in patients whose coronary aneurysms regressed within several years after acute KD. Coronary computed tomography angiography and flow-mediated dilatation might be useful for the detection of mild sequelae of KD non-invasively.

Significance of transient left ventricular wall thickening in acute lymphocytic myocarditis

Transient left ventricular (LV) wall thickening is observed in patients with acute lymphocytic myocarditis. The present study was undertaken to clarify the significance of transient LV wall thickening in patients with this disease. The subjects comprised 25 patients with acute lymphocytic myocarditis. Echocardiography was used to measure the thickness of the interventricular septum (IVS) and the LV posterior wall (PW) at four time points after myocarditis onset – namely, on days 1–3, 6–8, 13–15, and 28–30 – to clarify the timing and frequency of wall thickening. The 25 patients were divided into a fulminant myocarditis group (n = 14) and a nonfulminant myocarditis group (n = 11), and the relationship between LV wall thickening and myocarditis severity was investigated. Left ventricular wall thickening was greatest on days 1–3 after myocarditis onset (IVS: 13.3 ± 3.2 mm; PW: 12.1 ± 2.6 mm), with this finding being noted in 14 of the 25 cases (56%). By days 6–8, the thickness of IVS had virtually normalized to 10.6 ± 1.6 mm (P < 0.0001) and that of PW to 10.2 ± 1.4 mm (P = 0.0006). The thickness of the IVS and PW on days 1–3 after myocarditis onset were 14.6 ± 3.7 and 13.0 ± 2.9 mm, respectively, in the fulminant group (P = 0.014), and 11.5 ± 0.9 and 10.9 ± 1.4 mm, respectively, in the nonfulminant group (P = 0.039). In lymphocytic myocarditis, LV wall thickening is greatest on days 1–3 after myocarditis onset and improves to near normal by days 6–8. Such transient LV wall thickening occurs in approximately 50% of cases. Left ventricular wall thickening was more marked in the fulminant compared with the nonfulminant group.

A case of unicuspid aortic valve associated with a single coronary artery and ventricular septal defect

The patient was a 26-year-old man who had undergone patch closure of a ventricular septal defect at 2 years of age. After this surgery, his condition was satisfactory until he visited our hospital for treatment of paroxysmal supraventricular tachycardia in November 2000. Echocardiography revealed moderate to severe aortic valve regurgitation and dilatation of the left ventricle and ascending aorta. These echocardiographic abnormalities were attributed to a bicuspid aortic valve. Coronary angiography suggested the presence of a single coronary artery originating from the left Valsalva sinus. We performed Bentall’s operation in January 2003. The intraoperative findings revealed that the aortic valve consisted of an extensively calcified single cusp, and there was a single coronary artery originating from the left Valsalva sinus. Because adult patients with a unicuspid aortic valve are rare, and no cases of unicuspid aortic valve associated with a single coronary artery have been reported, we herein report this case with a review of the literature.

Questionnaire survey on the state of routine echocardiographic examinations in Japan : second report

We mailed questionnaires to 748 registered medical sonographers [RMSs (cardiology)] to gather information for a large-scale survey of RMSs in May 2000. We wanted to evaluate the current state of routine echocardiography in Japan. Altogether, 530 (70.9%) of these sonographers responded; 18 respondents employed by equipment manufacturers were excluded from the start of the study, and 20 others later found to be employed by equipment manufacturers were also excluded. Responses from all personnel at a single institution were treated as a single response; 436 institutions were thus included in the survey. Most or all examinations were carried out by sonographers at 77.3% of the responding institutions but were performed mainly by physicians at 11.1% of the institutions. At least 80% of sonographer or physician working hours were used for echocardiographic examination at 18.9% of the surveyed institutions, whereas up to half the working hours were devoted to echocardiographic examinations at 67.0% of the institutions. The most frequently reported examination time was 30–40 min [35.6% (n = 116) of the institutions], whereas 32.8% (n = 107) of the institutions indicated durations of 10–20 min per examination. Left ventricular (LV) dimensions and wall thickness were measured on M-mode images in all patients at 14.1% (n = 59) of the institutions and mainly on M-mode images but from two-dimensional echocardiography in problematic patients at 74.2% (n = 311) of the institutions. The LV ejection fraction was calculated from LV dimensions at 55.7% (n = 205) of the institutions and from the LV cross-sectional area at 44.3% (n = 163) of the institutions. The LV ejection fraction was estimated visually at 57.0% of the institutions. Only 5.5% (n = 22) of the facilities always scored the wall motion. Pulsed Doppler echocardiography was used to assess LV inflow in all patients at 65.9% of the institutions; regurgitation and shunting were always assessed quantitatively at only 2% (n = 8). Comments concerning image quality were reported in all cases or in cases of poor image quality at 98% of the institutions, and the sonographer was also involved in writing the diagnostic report at 94% of institutions. Echocardiography is less expensive than other diagnostic imaging methods, and its importance is thus likely to continue to increase. Echocardiographic examinations should be carried out by skilled RMSs and physician echocardiographers; and an accurate, readily comprehensible report of the findings should be provided promptly to the referring physician. More such surveys are required to ensure that these practices are adopted.

Altitude-Induced Pulmonary Hypertension on One-Day Rapid Ascent of Mount Fuji: Incidence and Therapeutic Effects of Sildenafil

Exposure to high altitudes especially with rapid ascent may induce hypoxic pulmonary vasoconstriction (HPV) and pulmonary hypertension (PH) possibly leading to life‐threatening high‐altitude pulmonary edema (HAPE). The aim of the study was to evaluate the incidence of PH on a 1‐day rapid ascent up Mount Fuji (3775 m) in recreational climbers and also to determine the effectiveness of sildenafil for this rapid ascent‐induced PH as measured by echocardiography.

Left ventricular function in asthmatic children chronically treated with theophylline evaluated by exercise Doppler echocardiography

To evaluate the chronic effects of theophylline on cardiac function, M-mode and pulsed Doppler derived variables were measured at rest and the suprasternal continuous wave Doppler measurement of ascending aortic flow was used during treadmill exercise testing. Subjects consisted of 13 children with stable asthma (mean 11.7±2.2 years) who were treated with theophylline for at least one year and 16 age-matched, untreated normal volunteers. In the resting state, the chronic administration of theophylline seemed to produce a slight increase in percent fractional shortening, outflow peak velocity and atrial contribution to ventricular filling in the asthmatic children as compared to normals, but these changes were not statistically significant. The asthmatic children showed significantly lower values than the controls in exercise induced changes in the peak velocity, stroke index and cardiac index, but not in the heart rate. Therefore, chronic administration of theophylline appears to have a minimal effect on resting cardiac function, but a possibly deleterious effect on the cardiac response to exercise testing.