Effective Management of Atrioventricular Interval for Paroxysmal Atrial Fibrillation That Developed After DDDR Pacemaker Implantation in a Sick Sinus Syndrome Patient.

A 68-year-old man with sick sinus syndrome (SSS) was referred to our department for pacemaker implantation. After implantation of a pacemaker with rate-responsive dual chamber (DDDR) mode and minimized ventricular pacing (MVP) functions, paroxysmal atrial fibrillation (PAF) repeatedly developed. Pacemaker memory showed that the intrinsic atrioventricular (AV) (atrial pacing-ventricular sensing [Ap-Vs]) interval was paradoxically prolonged during rate-responsive atrial single-chamber (AAIR) mode rapid pacing because of MVP. Accordingly, to eliminate the paradoxical prolongation of the AV interval during rapid atrial pacing, we changed MVP to medium AV hysteresis and conducted DDDR mode pacing with rate-dependent AV delay. PAF then sharply decreased without antiarrhythmic drugs.

Prevalence and distribution of sarcomeric gene mutations in Japanese patients with familial hypertrophic cardiomyopathy.

BACKGROUND: Hypertrophic cardiomyopathy (HCM), which is inherited as an autosomal dominant trait, is the most prevalent hereditary cardiac disease. Although there are several reports on the systematic screening of mutations in the disease-causing genes in European and American populations, only limited information is available for Asian populations, including Japanese. METHODS AND RESULTS: Genetic screening of disease-associated mutations in 8 genes for sarcomeric proteins, MYH7, MYBPC3, MYL2, MYL3, TNNT2, TNNI3, TPM1, and ACTC, was performed by direct sequencing in 112 unrelated Japanese proband patients with familial HCM; 37 different mutations, including 13 novel ones in 5 genes, MYH7, MYBPC3, TNNT2, TNNI3, and TPM1, were identified in 49 (43.8%) patients. Among them, 3 carried compound heterozygous mutations in MYBPC3 or TNNT2. The frequency of patients carrying the MYBPC3, MYH7, and TNNT2 mutations were 19.6%, 10.7%, and 8.9%, respectively, and the most frequently affected genes in the northeastern and southwestern parts of Japan were MYBPC3 and MYH7, respectively. Several mutations were found in multiple unrelated proband patients, for which the geographic distribution suggested founder effects of the mutations. CONCLUSIONS: This study demonstrated the frequency and distribution of mutations in a large cohort of familial HCM in Japan.

Negatively charged low-density lipoprotein is associated with atherogenic risk in hypertensive patients.

Negatively charged low-density lipoprotein (LDL), generated via multiple processes such as oxidation, acetylation, or glycosylation, plays a key role in the initiation and progression of atherosclerosis and related diseases. Anion-exchange high-performance liquid chromatography (AE-HPLC) can subfractionate LDL into LDL-1, LDL-2, and LDL-3 based on LDL particle charge, but the clinical significance of LDL subfractions has not yet been elucidated. The aim of this study was to determine the clinical significance of these fractions with particular regard to atherogenic risk in hypertensive patients. Ninety-eight patients with essential hypertension (age 67.0 ± 10.7 years; 54 males) were enrolled in the present study. The relationships between LDL subfractions and atherogenic risk factors, including lipid profiles, blood pressure and plasma 8-isoprostane as a marker of oxidative stress, were examined. LDL-1 levels were significantly and negatively correlated with body mass index (r = -0.384, p < 0.001), systolic blood pressure (r = -0.457, p < 0.001), non-high-density lipoprotein cholesterol levels (r = -0.457, p < 0.001) and 8-isoprostane levels (r = -0.415, p < 0.001). LDL-3, which is the most negatively charged fraction of total LDL, was significantly and positively correlated with these parameters (r = 0.267, 0.481, 0.357, and 0.337, respectively). LDL-1 levels were significantly lower (p < 0.001), and LDL-2 and LDL-3 levels were significantly higher (each p < 0.001) in patients with poorly controlled hypertension than in patients with well-controlled hypertension. In addition, an increase in the total number of traditional risk factors at time of study participation, but not previous diagnosis, was associated with a decrease in LDL-1 levels and increases in LDL-2 and LDL-3 levels. These data suggest that LDL subfractions are associated with multiple atherogenic risk factors and that treatment to modify these risk factors could result in changes in LDL subfraction levels. In conclusion, LDL subfractions isolated by AE-HPLC may represent a marker of atherogenic risk in patients with hypertension.

Correlation between Transient Hypotension and Exclusively Exercise-induced Symptoms of Two-to-One Atrioventricular Block.

A 62-year-old woman with activity-dependent two-to-one atrioventricular block (2:1AVB) and a normal left ventricular ejection fraction was referred to our department for the evaluation of exclusively exercise-induced marked symptoms. The treadmill test helped establish a clear correlation between 2:1AVB and symptoms. The test results demonstrated that exercise-induced marked symptoms were attributed to abrupt transient hypotension combined with relative bradycardia, probably due to increased diastolic mitral and tricuspid regurgitation because of 2:1AVB during moderate-to-heavy exercise. After pacemaker implantation for 2:1AVB, the symptoms and transient hypotension disappeared, and her exercise capacity improved.

Fibrotic response to angiotensin II is blunted in the kidney, but not in the heart, in insulin-sensitive long-lived transgenic dwarf rats.

Insulin resistance is a characteristic feature of cardiovascular and renal diseases, and angiotensin II (Ang II) has been suggested to induce insulin resistance. The aims of this study were to elucidate the effect of chronic Ang II infusion on vascular reactivity and organ damage in insulin-sensitive rats. We confirmed the following three points. First, there was no significant difference in pressor response to chronic Ang II infusion (600 ng/kg/min) between insulin-sensitive transgenic rats (Tg) and control rats (C). Second, there was no significant difference in cardiac hypertrophy and fibrosis by chronic Ang II infusion between the two groups. However, third, fibrotic response to chronic Ang II infusion evaluated by histopathological scoring in the kidney was significantly decreased in insulin-sensitive transgenic rats (renal fibrosis and nephropathy score: C+Ang II vs Tg+Ang II; 2.5 vs 1.3; p<0.05). Furthermore, the expression of TGF-beta, a fibrosis indicator, was also significantly suppressed in the kidneys of the transgenic rats (TGF-beta1/GAPDH ratio: C+Ang II vs Tg+Ang II; 1.15 vs 0.81; p<0.05). This result indicates that the growth hormone/insulin-like growth factor-1 axis is critically involved in the development of renal injury and fibrosis, rather than hypertension, cardiac hypertrophy, and cardiac fibrosis induced by chronic Ang II administration.

[Plasma B-type natriuretic peptide (BNP) measuring].

Brain or B-type natriuretic peptide (BNP) is a potent natriuretic, diuretic and vasorelaxant peptide and inhibits sympathetic tone, the renin-angiotensin-aldosterone system, and synthesis of vasoconstrictive molecules. The major source of plasma BNP is the cardiac ventricles. Elevated plasma BNP concentrations correlate with increased left ventricular (LV) filling pressure. Therefore BNP is a useful biomarkers as a screening tool for LV dysfunction. It also is a strong diagnostic indicator for both systolic and diastolic LV dysfunction. Measurement of plasma BNP is proved to be not only an efficient but also a cost effective screening tool for identifying patients with acute dyspnea of unknown etiology.

Surgical repair of pulmonary artery dissection in a patient with 10-year history of Takayasu's arteritis.

Pulmonary artery (PA) dissection is a rare but life-threatening event, predisposing to sudden cardiac death and cardiogenic shock, and generally occurs in patients with underlying pulmonary hypertension. We report a case of surgical repair of PA dissection in a patient with 10-year history of Takayasu's arteritis and with no diagnosis of pulmonary hypertension.

GH suppresses TGF-beta-mediated fibrosis and retains cardiac diastolic function.

The aims of this study were to elucidate the molecular mechanism by which growth hormone (GH) excess is anti-fibrotic in vitro and in vivo model. The in vivo model GH excess showed a significant increase of relative wall thickness with no concomitant disturbance of cardiac diastolic function. Western blot for extracellular matrix (ECM) structural proteins showed minimal change in the GH treatment group, compared to an Angiotensin II (Ang II) subpressor dose group. In cultured cardiac fibroblasts, we investigated the abundance of ECM proteins, phosphorylation of p38 mitogen-activated protein kinase (MAPK), and transforming growth factor-beta (TGF-beta)-specific transcriptional activity. GH down-regulated the expression of PAI-1 and fibronectin proteins activated by TGF-beta. In reporter assays, GH, but not insulin-like growth factor-1 (IGF-1), reduced TGF-beta-specific transcriptional activity. Moreover, GH markedly down-regulated TGF-beta-induced phosphorylation of p38 MAPK. These results demonstrated that a chronic excess of GH have an anti-fibrotic effect on cardiac remodeling, probably through a down-regulation of TGF-beta signaling via de-phosphorylation of p38 MAPK.

A rare case of aortic tube graft occlusion 35 years after coarctectomy.

A 52-year-old male with a history of repair of aortic coarctation by prosthetic tube graft replacement 35-years ago developed anterior spinal artery syndrome caused by acute functional occlusion of the aorta at the repair site where pseudoaneurysm formation was observed. The patient was rescued by an emergency axillofemoral bypass, and residual hypertension in upper limbs was improved by elective ascending aorta-descending aorta bypass grafting.

Sotalol-induced coronary spasm in a patient with dilated cardiomyopathy associated with sustained ventricular tachycardia.

A 54-year-old man with severe left ventricular dysfunction due to dilated cardiomyopathy was referred to our hospital for symptomatic incessant sustained ventricular tachycardia (VT). After the administration of nifekalant hydrochloride, sustained VT was terminated. An alternate class III agent, sotalol, was also effective for the prevention of VT. However, one month after switching over nifekalant to sotalol, a short duration of ST elevation was documented in ECG monitoring at almost the same time for three consecutive days. ST elevation with chest discomfort disappeared since he began taking long-acting diltiazem. Coronary vasospasm may be induced by the non-selective beta-blocking properties of sotalol.

Hypercalcemia due to vitamin D intoxication with clinical features mimicking acute myocardial infarction.

We report a case of hypercalcemia in an elderly patient due to vitamin D intoxication with clinical features and electrocardiogram (ECG) findings mimicking acute myocardial infarction. A 78-year-old man was referred to our department with symptoms of general fatigue, anorexia and chest pain. The ECG demonstrated ST elevation in leads V1 to V3 and diffuse T wave flattening, resulting in myocardial infarction being suspected. However, his symptoms, including chest pain, gradually improved and the ECG returned to normal in accordance with a fall in his serum calcium level. We introduce the use of QaTc interval shortening in differentiating ST-T changes of hypercalcemia from those of true myocardial ischemia.

Segmental mediolytic arteriopathy involving celiac to splenic and left renal arteries.

A 46-year-old man presented with a huge splenic artery dissecting aneurysm that had been incidentally found and was successfully resected before rupture. The histopathologic findings were compatible with segmental mediolytic arteriopathy (SMA). Simultaneous involvement of the left renal and right common iliac artery was observed. The patient was also found to have an adrenocortical adenoma, gastrointestinal stromal tumor, hepatocellular carcinoma and schizophrenia. The relationship between SMA and other accompanying diseases was discussed.

Culprit segments identified by optical coherence tomography in patients with acute myocardial infarction: two case reports.

The high resolution of optical coherence tomography (OCT) provides detailed information about coronary plaque morphology, which enables the mechanism of acute myocardial infarction to be evaluated. We describe two patients with acute myocardial infarction in whom culprit segments were identified by OCT, but not by either coronary angiography or intravascular ultrasound.

A case of mixed connective tissue disease complicated with hypertrophic obstructive cardiomyopathy.

A 54-year-old female was diagnosed as mixed connective tissue disease (MCTD) complicated with secondary Sjögren's syndrome. Although she had no dyspnea on exertion, the chest X-ray showed cardiomegaly with interstitial pneumonia. The echocardiogram demonstrated asymmetric hypertrophy of the interventricular septum. Diagnosis of hypertrophic obstructive cardiomyopathy (HOCM) was confirmed by left ventriculography and myocardial biopsy. She was treated with prednisolone, resulting in improvement of swollen hand, elevated muscle enzymes and interstitial pneumonia. A rare complication of HOCM with MCTD was described.