The role of cardiac adenosine triphosphate-sensitive K+ (K(ATP)) channels induced by angiotensin II type 1 (AT1) receptor antagonist, CV-11974, on myocardial metabolism and contraction during ischemia, and reperfusion by the phosphorus 31-nuclear magnetic resonance in Langendorff-perfused rabbit hearts was investigated. After 20 min of continuous normothermic global ischemia, 30 min of postischemic reperfusion was carried out. CV-11974 with or without the K(ATP) channel blocker, glibenclamide, or the bradykinin B2 receptor antagonist, D-Arg-[Hyp3,D-Phe7]bradykinin, was administered 40 min prior to the global ischemia. Adenosine triphosphate (ATP), creatine phosphate (PCr), inorganic phosphate (Pi), intracellular pH (pHi), left ventricular systolic developed pressure, left ventricular end-diastolic pressure (LVEDP), and coronary flow were measured. Twenty-eight hearts were divided into 4 experimental groups consisting of 7 hearts each. Group I consisted of controls, Group II perfused with CV-11974 (10(-6) mol/L), Group III perfused with CV-11974 (10(-6) mol/L) in combination with glibenclamide (10(-6) mol/L), and Group IV perfused with CV-11974 (10(-6) mol/L) in combination with D-Arg-[Hyp3,D-Phe7]bradykinin (10(-6) mol/L). Group II showed a significant inhibition of the decrease in ATP during ischemia and reperfusion compared with Group I (p<0.01), being 42+/-3% and 19+/-4% at ischemia, 69+/-3% and 47+/-4% at reperfusion in Group II and Group I, respectively. Group II also showed a significant inhibition of the increase in LVEDP during ischemia and reperfusion compared with Group I (p<0.01), being 13+/-4 mmHg and 52+/-8 mmHg at ischemia, 8+/-2 mmHg and 26+/-5 mmHg at reperfusion in Group II and Group I, respectively. However, Group II did not inhibit the decrease in ATP and the increase in LVEDP during ischemia and reperfusion. Group IV also showed no inhibition of the aforementioned parameters during the same period. These results suggest that CV-11974 has a significant beneficial effect for improving myocardial energy metabolism and relaxation during both myocardial ischemia and reperfusion, which is provided by K(ATP) channels and bradykinin B2 receptor. The cardioprotective quality of the AT1 receptor antagonist is caused by the K(ATP) channels that are mediated by the bradykinin B2 receptor.
A 64-year-old male with unstable angina underwent direct stenting in the proximal and mid-left anterior descending coronary artery (LAD) lesions. Although coronary angiography showed a good result, intravascular ultrasound imaging revealed a dissection flap protruding through the struts of the stent in the proximal LAD. Another stent was deployed in the first stent (stent-in-stent) to seal it. The patient's in-hospital course was uneventful. Subacute stent thrombosis was not observed.
The usefulness of glucose-insulin-thallium-201 (GI-Tl) infusion single photon emission computed tomography (SPECT) in predicting reversible dysfunction has not been evaluated, so the present study recruited 20 patients with regional ischemic dysfunction for investigation. All patients underwent GI-Tl SPECT, post-stress Tl reinjection imaging and low dose dobutamine echocardiography. The diagnostic accuracy of these 3 techniques in predicting functional recovery was evaluated by receiver operating characteristic (ROC) analysis. In segments with functional recovery, regional Tl activities of GI-Tl SPECT were significantly higher than those of reinjection imaging (p<0.05), although there were no significant differences in segments without recovery. The area under the ROC curve for GI-Tl SPECT (0.75+/-0.06) was greater than that for reinjection imaging (0.68+/-0.07). The optimal cutoff values to identify viable myocardium were considered to be 55% of peak activity for GI-Tl SPECT and 50% for reinjection imaging. At this cutoff point, the sensitivity and specificity for detection of functional recovery were, respectively, 85% and 61% for GI-Tl SPECT, and 73% and 61% for reinjection imaging. Dobutamine echocardiography had the same sensitivity (85%), but lower specificity (48%) than GI-Tl SPECT. Continuous infusion of GI-Tl solution enhances regional Tl uptake compared with conventional post-stress reinjection imaging. This study suggests that GI-Tl SPECT is superior to reinjection imaging and dobutamine echocardiography in predicting functional recovery after ischemic left ventricular dysfunction.
Constrictive pericarditis (CP) is an unusual sequela of cardiac surgery, so the present study evaluated the clinical characteristics of patients with CP after coronary artery bypass grafting (CABG). Four hundred and sixty-three patients who underwent isolated CABG between January 1989 and March 1999 were examined retrospectively. The first choice of treatment for postoperative pericardial effusion was non-steroid anti-inflammatory agents, and an increased dose of diuretics. The second treatment choice was corticosteroids or pericardial drainage. When CP was suspected during the follow-up period (mean, 54+/-31 months), cardiac catheterization was carried out to establish the diagnosis. Of the 463 patients undergoing CABG, there were 11 (2.4%) who developed CP after surgery. The median time to the onset of symptoms after CABG was 4 weeks (range, 3-96 weeks). On univariate and multivariate analysis, normal left ventricular ejection fraction, warfarin administration, and early postoperative pericardial effusion were significantly associated with a greater potential of postoperative CP. The effusion was bloody in all cases of pericardial drainage despite warfarin therapy. Not draining the postoperative effusive pericardial effusion was a risk factor for the development of CP. Pericardial drainage for patients with significant effusion after CABG is important for the prevention of subsequent CP, especially in those patients being treated with warfarin or with normal left ventricular function.
Glycogen storage disease (GSD) types II, III, IV, and V may be associated with cardiomyopathy, but, with the exception of type III GSD, adult cases are extremely rare. A 62-year-old man was found to have GSD and a concomitant left ventricular aneurysm. He had been comparatively well until the age of 62 years, although he had suffered a cerebral infarction at the age of 35 years. The damage caused by glycogen deposition was strictly confined to the myocardium. Left ventriculography revealed a left ventricular aneurysm in the apex. The serial change on electrocardiogram, as well as the findings of the echocardiogram and of cardiac catheterization, resembled those of the dilated phase of hypertrophic cardiomyopathy. However, a left ventricular endomyocardial biopsy specimen revealed central vacuolar degeneration of myocytes with depositions of glycogen. The GSD type remains unknown in the present patient, because the activity of debranching enzyme (type III) measured from the skeletal muscle specimen was normal, whereas that of acid maltase (type II) was slightly low. It is possible that there is a specific malfunction of the acid maltase of the myocardium in the present patient.
The present study examined the ability of dual-chamber (DDD) pacing to improve symptoms and exercise tolerance in patients with non-obstructive hypertrophic cardiomyopathy (HNCM). Seven patients with HNCM who had failed to benefit from pharmacotherapy participated in the study. The New York Heart Association (NHYA) functional class status and exercise tolerance, which was determined by the treadmill exercise test, were recorded and an echocardiographic observation was performed before, and 1 week, 3 months and 1 year after the implantation of a permanent DDD pacemaker. The atrioventricular delay (AVd) was determined by measuring the point of peak rapid filling velocity and maximum cardiac output (CO). Two patients were not implanted with a permanent pacemaker because their CO and blood pressure decreased or because palpitation occurred during temporary pacing. The ratio between early and late peaks of flow velocity (1.56, 1.21,0.95, and 0.86 before implantation and 1 week, 3 months and 1 year after implantation, respectively); deceleration time (ms: 263.2, 217.6, 204.6, 187.0); peak filling rate (ml/s: 146.2, 204.0, 233.2, 243.6); NYHA functional class status (2.0, 1.8, 1.6, 1.4); and exercise tolerance (s: 203, 264, 403, 480) were significantly improved after implantation. However, left ventricular dimension, percent fractional shortening, ejection fraction, acceleration time and the isovolumic relaxation time were not changed significantly. In conclusion, DDD pacing improved symptoms and the NYHA functional class status, which is associated with improvement of left ventricular diastolic function. It is proposed that DDD pacing would be useful in patients not only with obstructive but also non-obstructive hypertrophic cardiomyopathy refractory to medical treatment, depending on the careful selection of subjects.
Previous studies have suggested that aging is associated with progressive arterial stiffness and widening of the pulse pressure, and pulse pressure has been found to be a risk factor of cardiovascular diseases. However, the effects of age, blood pressure (including pulse pressure) or atherogenic factors on thoracic aortic wall stiffness in patients with mild atherosis are unclear, so the present study used transesophageal echocardiography to examine 103 consecutive patients with various cardiovascular diseases. The extent of atherosis was evaluated in terms of intima-medial thickness (IMT), and 2 indices of wall stiffness in the aorta were calculated: elastic modulus and stiffness parameter (beta). In subjects with mild atherosis (IMT <1.0mm), age, body mass index, systolic blood pressure, pulse pressure, triglyceride level, and hypertension were factors significantly associated with high wall stiffness, and multiple logistic stepwise analysis revealed that age, pulse pressure, and triglyceride level were particularly significant.
The study tested the hypothesis that left atrial appendage (LAA) dysfunction in nonvalvular atrial fibrillation (NVAF) correlates with a prothrombotic state, and investigated whether the plasma natriuretic peptides are marker of LAA dysfunction in NVAF. Sixty-seven patients underwent transthoracic and transesophageal echocardiography. The left ventricular fractional shortening, left atrial diameter (LAD), LAA flow velocity and the grade of spontaneous echo contrast (SEC) were determined. The plasma concentrations of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), D-dimer, and thrombin-antithrombin III complex (TAT) were measured. The patients were divided into 2 groups according to LAA flow velocity: group I (LAA velocity <20 cm/s) and group II (LAA velocity > or = 20cm/s). The SEC score, D-dimer, TAT, BNP and LAD were significantly increased in group I. Based on simple linear regression analysis, SEC score (r=-0.638), LAD (r=-0.493), D-dimer (r = -0.485), BNP (r = -0.463), TAT (r = -0.455) and age (r = -0.314) were inversely correlated with LAA flow velocity. Multivariate analysis showed that SEC score (p = 0.0014) and plasma BNP level (p=0.0075) were independent negative predictors for LAA flow velocity. In conclusion, LAA dysfunction is associated with a prothrombotic state, and the plasma BNP concentration may serve as a determinant of LAA function in NVAF.
The athlete's heart is commonly characterized by an increase in left ventricular mass because of an increase in the left ventricular diastolic cavity dimensions or wall thickness or both. Endurance exercise also induces numerous cardiovascular adaptations, including increased vagal tone. However, the sympathetic function has not yet been precisely elucidated, so the present study evaluated cardiac sympathetic nerve function from metaiodobenzylguanidine (MIBG) images obtained 15 and 180 min after the injection of 123I-MIBG at a dose of 111 MBq. The ratio of heart/mediastinum count (H/M) and the washout rates of 123I-MIBG (WR) were calculated in 25 consecutive patients who were athletes (aged 52+/-13 years) and 23 normal subjects. There was a significant difference in the H/M between the athletic and normal hearts (2.3+/-0.3 vs 2.6+/-0.3, p<0.01, Scheffe's test). An increased WR was observed in the athletes group when compared with the normal group (34+/-4 vs 28+/-3, p<0.01), and there was a significant correlation between WR and the left ventricular mass index (r=0.578, p<0.01). Prolonged exercise training may alter cardiac sympathetic nerve function, which can be detected by MIBG imaging.
The postpericardiotomy syndrome is a well-known complication of opening and manipulating the pericardium. The occurrence of this syndrome following transvenous pacemaker insertion is very rare, and only 5 cases have been reported to date. The present patient repeated this syndrome 3 times in a short period following 3 different interventional techniques: a temporary transvenous pacemaker, a permanent transvenous pacemaker and surgical pericardiotomy.
Spontaneous degeneration of rapid atrial fibrillation (AF) to ventricular fibrillation has been documented in patients with hypertrophic cardiomyopathy (HCM) and Wolff-Parkinson-White (WPW) syndrome. However, the importance of rap
Rupture of the posterior wall of the left ventricle after mitral valve replacement is a dire complication associated with a very high mortality. This study reports a successful repair of type I left ventricular rupture, which occurred after mitral valve replacement concomitant with a left atrial reduction procedure, by combination of an intracardiac patch and an extracardiac buttress suture. In a case such as this, in which hemostasis is quite difficult to establish, this combination technique is particularly effective.
Left ventricular (LV) contractility is constantly changing during atrial fibrillation (AF), which is dependent on the force-interval relationships. However, no information has been available on LV relaxation in patients with both AF and impaired LV systolic function. LV pressure was measured with a catheter-tipped micromanometer and the time constant of isovolumic LV pressure decline (tau(bf)) was calculated with best exponential fitting from more than 10 consecutive beats. Patients with AF (5 with mitral valvular disease, 6 with idiopathic dilated cardiomyopathy, and 1 with no underlying disease) were subdivided into 2 groups: group A, with ejection fraction (EF) <0.5 (n=7); and group B, with EF > or =0.5 (n=5). Linear correlation coefficients (r) between tau and RR2, RR2/RR1, LV peak systolic pressure (peak LVP) were calculated. Although tau did not show a discrepancy between the 2 groups, tau(bf) correlated better with RR2/RR1 only in the group A patients. The relation between tau and peak LVP showed a good correlation with a steep slope (R, Deltatau/Deltapeak LVP) only in the group A patients (accentuated afterload-dependence). R was significantly different between the 2 groups. Thus, a beat-to-beat analysis of tau may be a practical and feasible way for detecting LV relaxation abnormality in patients with AF.
A 64-year-old man was admitted to hospital under the suspicion of unstable angina pectoris. Coronary angiography showed that he has a single coronary artery originating from the right coronary artery (RCA) without significant fixed stenosis. Acetylcholine was superselectively infused into the left main coronary artery (LMCA), and confirmed the coronary vasospastic occlusion associated with chest pain and elevation of the ST-segment in the precordial leads. This is the first report of the induction of a totally occlusive spasm of the LMCA of a patient with a RCA type single coronary artery, and this case suggests that spasm of the aberrant coronary artery is a potential mechanism for sudden death in patients with a single coronary artery.
The present study was performed to determine whether a multilineal regression model based on the early diastolic transmitral flow peak velocity (E) and the propagation velocity of early diastolic inflow (PV) could estimate the pulmonary capillary wedge pressure (PCWP). PCWP and Doppler variables were simultaneously recorded in 30 patients. PCWP was estimated by multilinear regression analysis using E and PV. The predictive accuracy of the equation obtained from the analysis was tested prospectively in a separate group of 65 patients divided into 3 groups: left ventricular (LV) systolic dysfunction (Group A), LV hypertrophy (Group B), and preserved systolic function without hypertrophy (Group C). The initial results obtained in groups B and C, respectively, were: r=0.77; r=0.81. These results indicate that a multilinear regression model based on E and PV is a noninvasive method of accurately estimating PCWP in a variety of cardiac disease states.
Most patients diagnosed with secondary hemochromatosis have had repeated blood transfusions. Cardiac failure accounts for approximately one-third of the deaths associated with hemochromatosis. Liver dysfunction or hormonal disorders such as diabetes generally precede cardiac failure. A 23-year-old woman with hemochromatosis had, despite significant left ventricular dysfunction, liver function within the normal range on biochemical evaluation. She was treated for congestive heart failure and given desferoxamine intravenously. She did not have primary hemochromatosis, and had not received multiple blood transfusions or iron supplement. As a child the patient had been diagnosed with congenital non-spherocytic hemolytic anemia not requiring transfusion; thus, this is a unique case of secondary hemochromatosis.
The present study evaluated whether hyperinsulinemia is a predictor of restenosis after coronary balloon angioplasty in 69 patients who underwent elective coronary balloon angioplasty; patients were excluded if they were known diabetics being treated with insulin. Quantitative coronary angiography was performed before and after angioplasty and at follow-up. Restenosis was defined as the presence of greater than or equal to 50% stenosis at follow-up. Plasma insulin responses before, 30, 60, and 120 min after 75 g glucose load (OGTF) were measured. Plasma insulin levels were higher in patients with restenosis than in patients without restenosis. Minimal lumen diameter at follow-up was smaller, and percent diameter stenosis at follow-up was higher and late loss was greater in the highest sum of insulin levels during OGTT (Sigma insulin) quartile (0.95 +/-0.15 vs 1.47 +/-0.09 mm, p=0.005; 66.3 +/-5.8 vs 40.5 +/-3.3%, p=0.0003; 0.90 +/-0.15 vs 0.49 +/-0.08 mm, p=0.02). Even after adjustment for coronary risk factors and administration of angiotensin converting enzyme inhibitors, the association of hyperinsulinemia with restenosis leads to the conclusion that hyperinsulinemia is a strong risk factor for restenosis.
Doppler echocardiographic indices of left ventricular (LV) diastolic function are widely used to evaluate the cardiac function of patients with cardiac disease. However, there have been few reports about the relationship between Doppler indices and exercise capacity and so 44 patients with myocardial infarction were investigated by cardiopulmonary exercise testing and 2-D and Doppler echocardiography. Diastolic performance was assessed using Doppler transmitral flow velocity and pulmonary venous flow velocity. The ratio of peak E wave velocity and peak A wave velocity (E/A) correlated with peak oxygen consumption (peak Vo2) (R=0.72), and there was a negative correlation between the deceleration time of E velocity (Dct) and peak Vo2 or anaerobic threshold (AT) (R=-0.65, -0.62, respectively). The ratio of peak S wave velocity and peak D wave velocity (S/D) negatively correlated with peak Vo2 (R=-0.58). Left ventricular ejection fraction did not correlate to exercise capacity. These results suggest that the Doppler echocardiographic indices of LV diastolic function correlate with exercise capacity in patients with mild cardiac dysfunction.
The effects of gene transfer of the secreted form of fibroblast growth factor-2 (FGF-2) were tested using an adenovirus vector in the microembolized rabbit heart. Japanese white rabbits underwent an intracoronary injection of 25-microm microspheres followed by recombinant adenovirus vectors encoding a secreted form of FGF-2 (FGF group), LacZ (LacZ group), or saline (saline group). Left ventricular (LV) systolic function was serially assessed by echocardiography. Vascular density was measured at 14 days with Azan and CD31 staining. The development of collateral vessels was assessed by measuring myocardial blood flow before and after the occlusion of the left anterior descending coronary artery. Percent fractional shortening (%FS) decreased after the microembolization, and improved gradually for 14 days in the FGF group only (41+/-1% (FGF) vs 32+/-1% (LacZ), 31+/-1% (saline), p<0.01). The vascular density and myocardial collateral blood flow were significantly higher in the FGF group in comparison with other groups. Transcoronary arterial gene transfer of the secreted form of FGF-2 was beneficial for the recovery of LV systolic function and development of collateral vessels in the microembolized rabbit heart.
A 67-year-old woman with hypertrophic obstructive cardiomyopathy that was refractory to medical treatment underwent percutaneous transluminal septal myocardial ablation (PTSMA). The septal branch supplying the myocardium involved in the left ventricular outflow tract (LVOT) obstruction was identified by selective myocardial contrast echocardiography (MCE). MCE for the third and largest septal branch opacified the right side of the mid-septal myocardium and MCE for the second septal branch opacified the right side of the basal portion of the septal myocardium. Finally, contrast agent was injected into the first, small branch, which opacificied the myocardium protruding into the LVOT. Subsequently, septal myocardial ablation for this vessel with intracoronary alcohol was performed, followed by a reduction of the LVOT gradient and successful, dramatic improvement in the patient's clinical condition. Selective MCE was very useful to identify the appropriate septal branch for PTSMA and enabled maximal effect of this treatment with minimal myocardial damage.
