Tetsuhiro Yamano

Increased plasma brain natriuretic peptide level as a guide for silent myocardial ischemia in patients with non-obstructive hypertrophic cardiomyopathy

OBJECTIVES We measured plasma atrial/brain natriuretic peptide (ANP/BNP) levels at rest and during exercise and correlated the results with various clinical findings, particularly with myocardial ischemia, in asymptomatic hypertrophic cardiomyopathy (HCM). BACKGROUND In patients with HCM, ANP and BNP levels are elevated and exercise-induced myocardial ischemia is common. However, it has not yet been elucidated how these levels at rest and their change with dynamic exercise are related to ischemia. METHODS Levels of ANP and BNP were measured at rest and at peak exercise during (99m)Tc-tetrofosmin scintigraphy in 31 asymptomatic patients with non-obstructive HCM and in 10 control subjects. RESULTS Levels of ANP and BNP at rest and the change of ANP and BNP levels (PG/ML) from rest to exercise were significantly greater in HCM than in control subjects (ANP: rest, 53.2 +/- 31.8 vs. 11.6 +/- 6.1; exercise, 114.5 +/- 74.8 vs. 28.3 +/- 23.4. BNP: rest, 156.7 +/- 104.1 vs. 9.8 +/- 9.6; exercise, 201.6 +/- 131.5 vs. 13.2 +/- 14.5). Septal perforator compression (SPC) and exercise-induced ischemia were observed, respectively, in 20 (64.5%) and in 19 (61.3%) patients with HCM. The increment of ANP during exercise was similar between HCM subgroups with or without inducible ischemia. However, BNP levels at rest and BNP increments during exercise were significantly greater in the HCM subgroup with inducible ischemia than in the subgroup without (rest, 190.5 +/- 116.2 vs. 103.1 +/- 48.3; exercise, 250.5 +/- 142.2 vs. 124.2 +/- 58.6). Multiple logistic regression analysis revealed that SPC and BNP levels at rest were independently associated with exercise-induced ischemia. CONCLUSIONS Measurement of plasma BNP levels at rest may be useful in predicting silent myocardial ischemia in HCM.

Exercise-Induced Changes of Functional Mitral Regurgitation in Asymptomatic or Mildly Symptomatic Patients With Idiopathic Dilated Cardiomyopathy

It has remained unclear why functional mitral regurgitation (MR), even if it is of a mild degree, has prognostic importance in patients with idiopathic dilated cardiomyopathy (IDC). Exercise-induced changes in functional MR, which might be a clue to this question, have not been fully clarified. Thus, in this study, semisupine exercise echocardiography was performed on 32 asymptomatic or mildly symptomatic patients with IDC (29 men, mean age 45 +/- 14 years). The mean ejection fraction was 28 +/- 10% (range 13% to 45%). The effective regurgitant orifice (ERO) area of MR was measured, as well as echocardiographic parameters including mitral valve geometry. ERO at rest was associated best with systolic mitral tenting area (r(S) = 0.85, p <0.001). Functional MR did not newly appear during exercise in 9 subjects without MR at rest. In the remaining 23 subjects with functional MR at rest, all showed exacerbations of MR, with a median ERO of 10.5 mm(2) (interquartile range 6.3 to 16.5) to 18.7 mm(2) (interquartile range 9.5 to 29.3) (p <0.001). An increase in ERO was correlated best with the enlargement of tenting area (r(S) = 0.90, p <0.001) and was the strongest independent determinant of exercise duration (beta = -0.55, p = 0.002, multiple R(2) = 0.46). In conclusion, functional MR complicated with IDC was significantly exacerbated during exercise, with mitral valve deformation, which was strongly related to exercise intolerance; thus, the clinical impact of functional MR in patients with IDC could be more serious than can be expected by its degree at rest.

Two Cases of Delayed Cardiac Tamponade due to Pericarditis after Pulmonary Vein (PV) Isolation for Atrial Fibrillation

Catheter ablation is an established treatment for atrial fibrillation (AF). The incidence of major complications related to the procedure is reported to be 4.5%, and delayed cardiac tamponade (DCT) is a rare, although recently recognized, complication. However, the mechanisms underlying the development of DCT remain unclear. We herein report the cases of two men, both 49 years of age, who developed cardiac tamponade requiring pericardiocentesis a few weeks after undergoing pulmonary vein isolation for persistent AF. Physicians should explain to the patient the potential for DCT as a complication prior to performing catheter ablation and provide careful follow-up for at least a few weeks after the session.

Preoperative and Postoperative Mitral Valve Prolapse and Regurgitation in Adult Patients with Secundum Atrial Septal Defects

Background: Little attention is given to development of mitral regurgitation (MR) in adults with atrial septal defect (ASD). The aim of the study was to determine the associated factors of MR in ASD adults before surgical repair and the fate of moderate to severe MR after surgery. Methods: We examined 71 consecutive patients with secundum ASD (47 ± 16 years) who underwent surgical repair. Clinical and echocardiographic variables including size of left and right heart systems and severity of MR and tricuspid regurgitation (TR) were investigated before and early after surgery. Results: Before ASD closure, 14 patients (20%) had moderate to severe MR and 25 patients (35%) showed mitral valve (MV) prolapse. The ASD patients with moderate to severe MR showed worse cardiovascular symptoms, increased occurrence of atrial fibrillation and MV prolapse, and greater left ventricular (LV) end‐diastolic volume, left atrial area, and TR severity than those with none to mild MR (all P < 0.05). Among preoperative variables, TR severity, left atrial area, LV end‐diastolic volume, and MV prolapse were associated with preoperative MR severity in all the patients (all P < 0.03). Isolated ASD closure (n=46) decreased MV prolapse (P=0.008). Preoperative moderate to severe MR decreased after ASD closure with and without MV surgery (n=9 and 5, respectively; both P < 0.05). Conclusions: Preoperative MR severity was associated with TR severity, dilated left heart chambers, and MV prolapse. MR decreased after ASD closure with and even without MV surgery.

Assessment of left ventricular diastolic function by gated single-photon emission tomography: comparison with Doppler echocardiography

Gated single-photon emission tomography (SPET) is not yet an established procedure for the evaluation of left ventricular (LV) diastolic function. This study examined diastolic function derived from gated SPET in comparison with an established diagnostic tool, Doppler echocardiography. We examined 37 consecutive patients with normal sinus rhythm who underwent gated technetium-99m tetrofosmin SPET. A gated SPET program was used with a temporal resolution of 32 frames per R-R interval. We obtained the Doppler transmitral flow velocity waveform immediately before gated SPET image acquisition. Patients who showed a ratio of peak early transmitral flow velocity to atrial flow velocity (E/A) of >1 or whose R-R intervals differed by >5% between Doppler echocardiography and gated SPET were excluded from this investigation. We compared diastolic indices and presumed corresponding intervals in diastole using the two methods. The peak filling rate (PFR) derived from gated SPET correlated with the Doppler peak velocity of the early transmitral flow (E) wave (r=0.65) and deceleration of the E wave (r=0.71). The time to PFR and percent atrial contribution to LV filling from gated SPET correlated excellently with the Doppler LV isovolumic relaxation time (r=0.93) and the E/A ratio (r=−0.85), respectively. There was a significant linear correlation in all the intervals from the R wave to the presumed corresponding diastolic points. The point of PFR in gated SPET and the peak of the E wave in Doppler echocardiography generally coincided. The onset of filling in gated SPET tended to be closer to the second heart sound than the start of the E wave in Doppler echocardiography. We conclude that gated SPET permits the assessment of not only myocardial perfusion and LV systolic function but also diastolic function, although there may be some errors in detection of the precise beginning of LV filling.

Angioscopic observation in chronic thromboembolic pulmonary hypertension before and after balloon pulmonary angioplasty

: We here report the angioscopic assessment of inoperable peripheral chronic thromboembolic pulmonary hypertension in an 81-year-old man who was previously diagnosed with the disease. To assess the pathological morphology of the web lesion, pouch defect and band lesion, we used two types of angioscopic catheter: blood flow-maintaining type and blood flow-blocking type. Angioscopy revealed a heterogeneous thrombus that contained white organized thrombus, red fragile thrombus and yellowish thrombus. After three sessions of balloon pulmonary angioplasty, his pulmonary arterial pressure decreased and his symptom of dyspnea on exertion and desaturation were improved. Angioscopy displayed various forms of organized thrombus, and also allowed the detailed observation of lesions that were difficult to be observed by angiography.

Dual SPECT imaging with Tc-99m pyrophosphate and Tl-201 of circumferential subendocardial myocardial infarction in aortic stenosis without coronary artery stenosis.

An 88-year-old woman with aortic stenosis, who had demonstrated fever for several preceding days, complained of angina and orthopnea. Although the symptoms were suggestive of acute myocardial infarction, coronary angiography failed to demonstrate coronary artery stenosis. Dual SPECT with Tc-99m pyrophosphate and Tl-201 demonstrated an abnormal accumulation of the former tracer throughout the inner layers of the left ventricle, indicating circumfer- ential subendocardial infarction. Confirmation of this diagnosis is often difficult, and there have been only a few documented cases. However, the present images clearly depicted this unusual view of infarction in a patient with aortic stenosis but without coronary artery stenosis.

Brain natriuretic peptide concentration in pericardial fluid is independently associated with atrial fibrillation after off-pump coronary artery bypass surgery.

ObjectivesPostoperative atrial fibrillation is associated with the increased incidence of morbidities and mortality. Predisposing determinants of atrial fibrillation development after off-pump coronary artery bypass grafting remain unclear. We hypothesized that pericardial fluid natriuretic peptide concentrations have a predictive value for developing postoperative atrial fibrillation in patients who have undergone off-pump coronary artery bypass grafting. MethodsWe prospectively measured atrial natriuretic peptide and brain natriuretic peptide concentrations in plasma and pericardial fluid in 42 consecutive patients undergoing off-pump coronary artery bypass grafting, then continuously observed the occurrence of atrial fibrillation following off-pump coronary artery bypass grafting until the time of discharge. ResultsPostoperative atrial fibrillation was documented in nine patients (21%, atrial fibrillation group), and not in 33 patients (no atrial fibrillation group). Between the groups, there was neither significant difference in plasma atrial natriuretic peptide concentrations nor in pericardial atrial natriuretic peptide concentrations. Plasma brain natriuretic peptide concentrations were comparable in both groups [56.2 (interquartile range 42.7–102.8) vs. 35.2 pg/ml (13.8–75.0), P=0.07]. Pericardial fluid brain natriuretic peptide concentrations were significantly higher in the atrial fibrillation group than in the no atrial fibrillation group [188.0 (124.8–411.0) vs. 39.3 pg/ml (10.0–88.4), P=0.0001]. In a multivariable logistic regression model, pericardial brain natriuretic peptide concentration was significantly associated with a higher risk of postoperative atrial fibrillation (odds ratio=3.0 every 50 pg/ml increase; 95% confidence interval, 1.1–8.6; P=0.04). ConclusionOur results suggested that pericardial fluid brain natriuretic peptide concentration is independently associated with the development of atrial fibrillation after off-pump coronary artery bypass grafting.

Detection of saccular coronary artery aneurysm associated with coronary-pulmonary artery fistula using Tc-99m HSAD scintigraphy.

Radionuclide imaging of coronary aneurysm is rarely performed, because of the low incidence of the disease and difficulty in image construction. The authors describe a 68-year-old woman with a coronary aneurysm associated with a coronary-pulmonary artery fistula. Tc-99m diethylenetriamine pentaacetic acid human serum albumin (HSAD) cardiac pool SPECT clearly revealed a blood pool near the left ventricle. Coronary angiography revealed a coronary-pulmonary artery fistula with two saccular aneurysms. The use of Tc-99m HSAD cardiac pool SPECT to detect the saccular aneurysm is the preferred screening technique because it is less invasive.

Usefulness of peripheral arterial signs in the evaluation of aortic regurgitation

BACKGROUND Early diagnosis and optimal timing of surgical repair for chronic aortic regurgitation (AR) are topics of interest, because left ventricular compensation delays the clinical signs of the early stages of left ventricular dysfunction. Various physical signs have been described as indicators of chronic AR, but AR screening can be difficult depending on the proficiency of primary care providers. The recent use of the cardio-ankle vascular index (CAVI) measurement to assess peripheral atherosclerosis may detect AR objectively and simply because its arterial pulse wave configuration is closely related to the physical signs of AR. METHODS CAVI measurements include pulse pressure (PP), the difference in blood pressures between upper and lower limbs (ABD), ankle-brachial index (ABI), ejection time (ET), and upstroke time (UT). We evaluated the differences in CAVI parameters between AR group and age-matched control group, the relationships between CAVI parameters and the echocardiographic semi-quantitative measurements of AR severity such as left ventricular dimensions (Dd, Ds) and vena contracta (VC), and between the changes in CAVI parameters before and after aortic valve replacement. RESULTS ABD, PP, ET, ankle systolic pressure and ABI in the AR group were significantly higher than that in the control group. Brachial diastolic pressure and CAVI in the AR group were significantly lower than that in the control group. UT was lower than that in the control group (p=0.05). PP did not correlate with the semi-quantitative AR severity, but ABD was correlated with Dd, Ds, and VC and was negatively correlated with UT. The exaggerated ABD, PP, ET, and ABI were moderated after surgery. CONCLUSIONS CAVI parameters could be useful in the screening and serial follow-up of AR patients.