Beta-blocker therapy has been shown to improve cardiac function and prognosis in patients with idiopathic dilated cardiomyopathy (DCM). However, whether β-blockers reduce severe ventricular arrhythmias and sudden cardiac death has not been clarified. The present study was designed to investigate the effects of β-blockers on non-sustained ventricular tachycardia (VT) and sudden cardiac death in patients with DCM. Sixty-five patients with DCM treated with diuretics, digitalis and angiotensin-converting enzyme inhibitors were assigned to receive β-blockers (n=33) or not (n=32). Mean follow-up was 53±30 months. The echocardiographic indices of cardiac function, the incidence of non-sustained VT on Holter monitoring electrocardiograms, and sudden cardiac death rate were compared between the 2 groups. Comparable improvement in cardiac function on echocardiograms was found in the 2 treatment groups. The patient group treated with β-blockers showed a significant reduction in the prevalence of VT (from 43 to 15%, p<0.05) and the development of new episodes of VT (5 vs 16%) compared to the group without β-blockers. The sudden cardiac death rate did not differ between the 2 groups. The results of the present study suggest that β-blockers are effective in reducing severe ventricular arrhythmias in patients with DCM.
Lipoprotein(a) (Lp(a)) has a prothrombotic effect by modulating the fibrinolytic system. The purpose of the present study was to determine whether serum Lp(a) levels are associated with an increased risk of thromboembolism in chronic nonvalvular atrial fibrillation (NVAF). Clinical, laboratory and transesophageal echocardiographic data were collected in 172 consecutive, non-anticoagulated patients with chronic NVAF. Thirty-four patients (thromboembolic group) had a recent (<1 month) embolic event and/or a left atrial thrombus on transesophageal echocardiography. The thromboembolic group had a higher frequency of spontaneous echo contrast (94 vs 58%, p<0.0001), increased concentrations of Lp(a) (median: 31.5 vs 15.5mg/dl, p<0.0001) and fibrinogen (median: 352 vs 314mg/dl, p=0.0015), larger left atrial dimensions (median: 5.1 vs 4.8cm, p=0.0078), and reduced left atrial appendage (LAA) flow velocities (median: 9.5 vs 21.2cm/s, p<0.0001) than the nonthromboembolic group. Multivariate analysis identified 3 independent predictors of thromboembolism: Lp(a) level ≥30mg/dl (odds ratio (OR) 9.5, 95% confidence interval (CI) 4.4-20.4, p<0.0001), LAA flow velocity of <20cm/s (OR 8.7, 95% CI 3.3-23.0, p=0.0003) and a fibrinogen concentration of <377mg/dl (OR 3.2, 95% CI 1.5-6.9, p=0.0201). The Lp(a) elevations and reduced LAA flow velocities are independently associated with thromboembolism in chronic NVAF.
A method to repair endovascular aneurysms with covered stents has recently been developed. In the present paper, the implantation of a covered stent through a 12Fr sheath by the puncture method for the treatment of an isolated aneurysm of the right common iliac artery is reported. The aneurysm was less than 3cm in diameter, and computed tomography showed no signs of aneurysm rupture, but the patient nonetheless complained of right lower abdominal pain and constipation. It was decided to implant a covered stent in lieu of surgical repair because it was difficult to prove a causal relationship between the aneurysm and the patient’s complaints. Fortunately, after implantation, the symptoms were resolved. In conclusion, it is possible to choose this less invasive type of therapy for the treatment of an isolated iliac artery aneurysm if the patient complains only of general malaise and there are no certain signs of an impending rupture, although surgery should be indicated regardless of aneurysm size.
It remains uncertain whether established risk factors for coronary heart disease in middle-aged persons can be generalized to elderly persons. Based on a case-control study, risk factors for nonfatal acute myocardial infarction (AMI) were assessed separately in middle-aged (40-64 years) and older (65-79 years) Japanese. Eligible cases were patients who were admitted to 22 collaborating hospitals for the first AMI between September 1996 and January 1998. Community controls were recruited by using the resident registers of the municipalities with individual matching by gender, year of birth (within 2 years), and proximity in residence. The present study used 384 sets of 384 cases and 656 controls. Smoking, hypertension, and angina pectoris were associated with an increased risk of AMI, and alcohol use and leisure-time exercise were related to a decreased risk of AMI in the elderly as well as in middle-aged persons. There was no apparent relation between body mass index and AMI in either middle-aged or older adults. Diabetes mellitus was significantly associated with an increased risk of AMI in older persons, but not in middle-aged persons. Hypercholesterolemia was related to an increased risk of AMI in middle-aged individuals alone. The findings suggest that risk factors for AMI in the elderly are generally similar to those of middle-aged persons, but provide no evidence that hypercholesterolemia in the elderly is an important risk factor.
The characteristics of the second derivative of the photoplethysmogram (SDPTG) were clarified in children and young people, and the factors affecting the SDPTG wave pattern were examined. The study group comprised 775 healthy subjects aged 3-20 years (mean, 10±5). The blood pressure of the left brachial artery was determined in the resting sitting position and then the fingertip PTG and the SDPTG were automatically measured using a digital photoplethysmograph, with the sensor located at the cuticle of the second digit of the right hand. The values used were the b/a, c/a, d/a, and e/a ratios, and the SDPTG aging index (SDPTG-AI). With increasing age, the systolic blood pressure and height increased (r=0.52, 0.92). Aging decreased the b/a ratio and SDPTG-AI (r=-0.58, -0.67) and increased the c/a and e/a ratios (r=0.42 and 0.42). There was no significant correlation between blood pressure and indices of SDPTG. As height increased, the b/a ratio and SDPTG-AI decreased (r=-0.57, -0.71), whereas the c/a and e/a ratios increased (r=0.42 and 0.46). In males the SDPTG-AI decreased with age from 3 to 18 years and then increased, and in females it decreased with age from 3 to 15 years and then increased. Overall, the SDPTG-AI decreased with age between 3 and 18 years and then increased, forming a J curve. In the children’s and young people’s SDPTG, the b/a and SDPTG-AI decreased and the c/a and e/a ratios increased with age. The length of the vascular system and the inner diameter and wall thickness of vessels may modify the SDPTG wave pattern in the growth period. Thereafter, as the effects of these factors decrease, the increase in intravascular pressure and decreasing wall elasticity due to aging may affect the wave pattern.
Although fatty acid metabolism is reportedly impaired in myocardial hypertrophy, it is unclear whether the anti-hypertensive drugs are associated with improved fatty acid metabolism. In order to evaluate the effects of anti-hypertensive drugs on fatty acid metabolism and myocardial perfusion, the simultaneous uptake of iodine-125(125I)-15-(p-iodophenyl)-3-(R, S)-methylpentadecanoic acid (BMIPP) and thallium-201 (Tl) were measured in 3 groups of rats: (1) spontaneously hypertensive rats (SHR) without treatment (SHR-N), (2) SHR chronically treated with captopril (SHR-C), and (3) SHR chronically treated with hydralazine (SHR-H). Captopril and hydralazine were administered to their respective groups for 3 weeks from 12 weeks of age. The hearts were removed 10min after simultaneous intravenous injections of BMIPP and Tl and the 125I and 201Tl counts were measured to calculate the uptake ratio. The systolic blood pressure (SBP) in SHR-N was 222±10mmHg, whereas the SHR-C and SHR-H groups showed significant SBP reduction (156±11, and 158±10mmHg, respectively) (p<0.01 each). The heart/bodyweight ratio was significantly lower in SHR-C (2.48±0.09) than in SHR-N (2.74±0.11) (p<0.05). However, there was no significant difference in the heart/bodyweight ratio between SHR-N and SHR-H (2.65±0.09). The ratio of BMIPP uptake to Tl uptake (BMIPP/Tl) was significantly higher in SHR-C (0.71±0.13) than in SHR-N (0.50±0.09) (p<0.05). However, BMIPP/Tl in SHR-H (0.53±0.09) was similar to that in SHR-N. These results suggest that captopril improves fatty acid metabolism in the hypertrophied ventricle in SHR. The metabolic alterations may improve with left ventricular hypertrophy regression but are not effected by the reduction of blood pressure only.
Spatial heterogeneity in the refractoriness of the ventricular myocardium due to a regionally prolonged refractory period has often been observed in patients with cardiovascular disease as the substrate for functional reentrant tachyarrhythmias. The present study sought to determine how functional reentrant activity could occur due to the spatial heterogeneity, using numerical simulation. Spatial heterogeneity in the refractoriness was introduced into a two-dimensional array by the regionally prolonged refractory period expressed as a square cluster. Double stimulation, conducted from a single source, was introduced into 4 types of matrices, which differed in their level of spatial heterogeneity. A pseudoelectrocardiogram was calculated from these matrices. Spiral waves were initiated in all the matrices except for the lowest heterogeneous matrix. A vulnerable window of the coupling interval, which induced spiral waves, was observed and was wider in proportion to the level of the heterogeneity. A higher level of heterogeneity and more limited range of coupling intervals were required to sustain the spiral waves. Furthermore, in the pseudoelectrocardiogram, sustained spiral waves exhibited a waveform like that in torsades de pointes (TdP) and their transformation into ventricular fibrillation (VF). Spatial heterogeneity in refractoriness due to a regionally prolonged refractory period could be a substrate for functional reentrant tachyarrhythmias, possibly including TdP and VF.
A 48-year-old man with a history of hypertension and diabetes mellitus was hospitalized with sudden onset of severe chest pain. He was in cardiogenic shock with a systolic pressure of 60 mmHg. His electrocardiogram (ECG) showed ST-segment elevation in the precordial leads suggestive of acute anteroseptal myocardial infarction. The ST-segment returned to baseline after the systolic blood pressure rose to 100mmHg with the administration of sympathomimetic agents. Aortography and transesophageal echocardiography demonstrated type A aortic dissection and aortic regurgitation. Aortography and short-axis transesophageal echocardiography showed during diastole almost complete collapse of the true lumen of the ascending aorta caused by the intimal flap. The patient underwent surgical repair of the aortic dissection and implantation of Palmaz stents in the carotid arteries. Decreased blood pressure and the presence of aortic regurgitation accelerated the collapse of the true lumen during distole in the ascending aorta, resulting in functional obstruction of the left main coronary artery, which may have been related to ST-segment changes in this case.
We experienced a long-term survival case of primary cardiac lymphoma (PCL) demonstrating ventricular tachycardia (VT) as an initial sign, which was related to localized myocardial damage by lymphoma cells. A 70-year-old woman with sustained VT was admitted to the Kofu Municipal Hospital. VT ceased with the administration of disopyramide intravenously. The origin of the VT was the free wall of the right ventricular outflow tract (RVOT) as observed by electrocardiography on admission. A solitary mass in the free wall of the RVOT was found by echocardiography, chest computed tomographic scanning and magnetic resonance imaging. There was no evidence of extracardiac involvement. The patient was histologically diagnosed as PCL by endomyocardial biopsy. Chemotherapy started immediately after the diagnosis and the mass showed a marked reduction in size. After 8 cycles of chemotherapy, radiotherapy was performed. Pericardial thickness in the free wall of the RVOT developed without severe side effects. Complte remission has been maintained for 30 months after the initial diagnosis, and no recurrence and arrhythmias have been detected during the follow-up period. It was demonstrated that rapid diagnosis and chemotherapy followed by radiotherapy for PCL achieved better survival.
Resuscitation was possible in a case of fulminant myocarditis with refractory ventricular fibrillation (Vf) using a percutaneous cardiopulmonary support system (PCPS). A 46-year old Japanese man suddenly experienced cardiopulmonary dysfunction shortly after the onset of flu symptoms, was promptly diagnosed as having fulminant myocarditis and PCPS was immediately initiated. On the second day in the hospital, refractory Vf occurred, which lasted for approximately 2h despite repeated efforts to terminate it. Finally, a large dose of steroids was administered. From the third day of hospitalization and onwards, the Vf disappeared totally. The patient completely recovered from such a serious state in 6 months. During the following 3 years, he has had no clinical symptoms of worsening. As in this case demonstrates, most myocarditis is curable and invasive measures are very helpful in rescuing patients from the fulminant type with refractory Vf.
Although myocarditis from a series of autopsies of patients with systemic lupus erythematosus was frequently observed, the incidence of clinically apparent myocardial dysfunction was low. A 30-year-old woman with systemic lupus erythematosus was examined by echocardiography. An acoustic densitometry was followed at the left ventricular posterior wall throughout the clinical course. A decrease in the magnitude of cyclic variation of integrated backscatter (IB) was observed before treatment. Following the combined treatment, steroid and cyclophosphamide, a repeated ultrasonic tissue characterization showed an increase in the magnitude of cyclic variation of IB. It is thought that ultrasonic tissue characterization may be a useful method to evaluate the impairment of contraction, and to follow up the clinical course of myocardial involvement in systemic lupus erythematosus.
We report a patient with concealed Wolff-Parkinson-White syndrome who, following catheter ablation, demonstrated phase-3 and phase-4 retrograde block in a concealed accessory pathway. After an initial ‘apparently successful’ ablation, retrograde conduction was through the atrioventricular node during constant ventricular pacing. Ventricular extrastimulus testing was performed at a basic drive cycle length of 600 ms. Unexpectedly, ventricular extrastimuli at coupling intervals of 440-380 ms were conducted retrogradely over an accessory pathway, consistent with a phase-3 and phase-4 retrograde block in the accessory pathway. Residual accessory pathway conduction was eliminated in a single ablation session.
A 21-year-old woman had paroxysmal wide QRS tachycardia with a left bundle branch block configuration and a retrograde conducted P wave just behind the QRS complex. An electrophysiological study revealed antidromic atrioventricular tachycardia involving an atrioventricular connection with decremental conduction as the anterograde limb and normal atrioventricular node as the retrograde limb. During constant pacing from the high right atrium (HRA) at the cycle length (CL) of 600 ms, the QRS configurations were not identical to those during the wide QRS tachycardia or constant pacing at the CL of less than 500 ms. The process by which this arborized atrioventricular accessory pathway with the Mahaim fibers physiology was interrupted by radiofrequency catheter ablation is described. Radiofrequency energy was delivered to the site recording a Mahaim potential at the tricuspid annulus during constant pacing from the HRA at the CL of 429 ms. The stimulus-QRS interval gradually shortened as it reached the power plateau without changing the preexcited QRS configuration. Shortening of the conduction time over the Mahiam pathway might have resulted in changing of the propagation from a slow to fast conduction zone or acceleration in response to thermal effect in a node-like structure on the atrial insertion site.
The clinicopathologic findings of reversible ampulla-like ventriculogram of the left ventricle were studied in 8 elderly women and one middle-aged man. Their coronary arteriograms were normal, even in the 7 patients who had ST elevation on electrocardiogram. Coronary spasm was positive in only 2 of the 7 patients who received provocation tests. Biopsy specimens revealed focal myocyte injury. Normal coronary arteriograms during ST elevation and the presence of pathologic myocardial lesions were not consistent with a concept of stunned myocardium. The presence of myocardial lesions suggested that focal and disseminated myocardial damage had occurred.