Successful epicardial ablation of idiopathic mitral annular ventricular tachycardia from the great cardiac vein.

This case report describes idiopathic ventricular tachycardia (VT) originating from the anterolateral site of mitral annulus. Radiofrequency (RF) energy application at an endocardial site of mitral annulus could not eliminate the tachycardia. The earliest epicardial activation preceding the onset of the QRS complex by 34 ms was found at the great anterior cardiac vein just opposite to the endocardial ablation catheter, pace mapping provided an identical (12/12) match with the VT morphology at the site, and RF ablation effectively eliminated the VT from the great cardiac vein within the coronary venous system.

Premature ventricular contractions originating from the left ventricular septum: results of radiofrequency catheter ablation in twenty patients.

BACKGROUND: RFCA has been established as an effective and curative therapy for severely symptomatic PVC from the outflow tract in structurally normal hearts. However, it is unknown whether PVCs originating from the left ventricular septum, are effectively eliminated by RFCA. This study aimed to investigate electrophysiologic characteristics and effects of radiofrequency catheter ablation (RFCA) for patients with symptomatic premature ventricular contraction (PVC) originating from the left ventricular septum without including fascicular PVCs. METHODS: Characteristics of body surface electrocardiogram (ECG) and electrophysiologic recordings endocardiogram in a successful RFCA target were analyzed in 20 patients with symptomatic PVCs originating from the left ventricular septum. RFCA was performed using pace mapping and activation mapping. RESULTS: The QRS morphology of PVCs originating from the left ventricular septum is similar to that seen in fascicular tachycardia. Most of the PVCs originated from the left septum appears in the form of ventricular parasystole. The incidence of ventricular parasystole was 70%. Sustained ventricular tachycardia was not inducible by electrical stimulation and isoproterenol infusion in all 20 patients, ablation at the site recording the earliest Purkinje potential was not effective in all 20 patients, and Purkinje potentials were not identified at successful sites during point mapping. Sixteen patients were successful with RFCA using pace mapping and activation mapping, 3 failed, and 1 recurrent. CONCLUSION: Although the ECG characteristics of the PVCs arising from the left ventricular septum are similar to that seen in fascicular tachycardia, the electrophysiologic characteristics are different between the two types of PVCs. The distinguishing characteristic of the PVCs is that Purkinje potentials were not present at the site of successful ablation, suggesting a myocardial as opposed to fascicular substrate. RFCA is an effective curative therapy for symptomatic PVCs originating from the left ventricular septum (not from the left anterior and posterior fascicle).

Establishment of a canine model of cardiac memory using endocardial pacing via internal jugular vein.

BACKGROUND: Development of experimental animal models has played an important role in understanding the mechanisms of cardiac memory. The purpose of this study was to evaluate a new canine model of cardiac memory using endocardial ventricular pacing via internal jugular vein. METHODS: Twelve Beagle dogs underwent placement of a permanent ventricular pacemaker mimicking the use of pacemakers in humans and induction of cardiac memory by endocardial ventricular pacing. RESULTS: Cardiac memory was achieved in 11 of 12 attempts overall. Procedural mortality due to cardiac tamponade (n = 1) occurred in the first attempt. The T-wave memory persisted for 96 +/- 17 minutes and 31 +/- 6 days in the short-term and long-term cardiac memory groups, respectively. There were no significant differences in the heart rate, blood pressure and echocardiographic parameters in the animals between before and after ventricular pacing in the short-term and long-term cardiac memory groups. No significant pathologic changes with the light microscopy were found in the present study in all dogs. CONCLUSION: The model does require surgery but is not as invasive as an open-chest model. This canine model can serve as a useful tool for studying mechanisms of cardiac memory.

Pulse pressure index (pulse pressure/systolic pressure) may be better than pulse pressure for assessment of cardiovascular outcomes.

Pulse pressure (PP) is emerging as a major pressure predictor of cardiac disease. However, there are two major limitations for PP as an evaluation index. First, PP has alterability in the same individual. Second, PP is "floating", it has no relation to an absolute BP level. In order to overcome the defects of PP, we propose a novel parameter, "pulse pressure/systolic pressure" called "pulse pressure index (PPI)" for assessment of cardiovascular outcomes. On the basis of elastic chamber theory, the following equation can be derived: PPI=pulse pressure/systolic pressure=(Cs-Cd)/(Cs-C(0)), (Cs, Cd and C(0), arterial compliance at systolic pressure, diastolic pressure and zero-pressure, respectively). PPI can overcome the defects of PP and become a useful index in clinical evaluation for assessment of cardiovascular outcomes.

Protective effects of carvedilol in murine model with the coxsackievirus B3-induced viral myocarditis.

Carvedilol, a nonselective beta-blocker with additional alpha1-adrenergic blocking and antioxidant properties, has been shown to be cardioprotective in experimental myocarditis. However, the antioxidative effects of carvedilol have not been investigated in the setting of acute viral myocarditis. Therefore, this study investigated whether carvedilol protects against viral myocarditis primarily by its antioxidant and/or antiinflammatory properties. In a coxsackievirus B3 murine myocarditis model (Balb/c), effects of carvedilol and metoprolol on myocardial histopathological changes, cytokine levels, virus titers, malondialdehyde (MDA), and superoxide dismutase (SOD) contents were studied. Carvedilol markedly attenuated myocardial lesions and increased interferon-gamma and interleukin-12 production (cytokines) on day 7 with concomitant reduction of myocardial virus replication. In addition, only carvedilol decreased the content of MDA and increased the content of SOD on day 14. Metoprolol as well as bunazosin (a higly selective alpha1-adrenergic blocking agent) had no significant effects in this model. The results indicate that the superior protection of carvedilol in this model is probably the result of its antioxidative effects and the upregulation of antiinflammatory cytokines.

Inhibition of puerarin on pulmonary hypertension in rats with hypoxia and hypercapnia / 中国中药杂志

<p><b>OBJECTIVE</b>To study the effects of puerarin on pulmonary Vascular remodeling in rats with pulmonary hypertension induced by chronic hypoxia and hypercapnia.</p><p><b>METHOD</b>Forty male rats (180-220) g of grade two were randomly divided into five groups: normal control group (NC), hypoxia-hypercapnia 1, 2, 3 week groups (LH1, LH2, LH3) and hypoxia-hypercapnia 3-week + puerarin group (LHP3 group, puerarin intraperitoneal injection, 20 mg x kg(-1) x d(-1)). Collagen I, III and their mRNA were observed in pulmonary arterioles by the technique of immunohistochemistry and in situ hybridization.</p><p><b>RESULT</b>Light microscopy showed media thickness of pulmonary arterioles was much higher in LH3 group than that of NC group, and, vessel cavity turned more straiter in LH3 group than that of NC group. Howerer, the damage of pulmonary arterioles in LHP3 group was much slighter than that of LH3 group. The levels of plasma ET-1 and lung homogenates Hyr and MDA were much higher in rats of LH3 group than those of NC group (P < 0.01), and lower in LHP3 group than LH3 groups (P < 0.01). The activities of SOD in lung homogenates were significantly lowered in hypoxic and hypercapnic groups compared with control group (P < 0.01), but higher in LHP3 group than that of LH3 group. Plasma NO content of group LH was lower than that of group NC (P < 0.01), it was highter in group LHP3 than that of group LH3 (P < 0.01). Expression of collagen I and collagen I mRNA in pulmonary arterioles were significantly higher in rats of LH groups than those of NC group (P < 0.01), and they were lower in rats of LHP3 group than those of LH3 group (P < 0. 01). Expression of collagen III and collagen III mRNA were not significant difference among three groups.</p><p><b>CONCLUSION</b>Puerarin could improve pulmonary vascular remodeling in rats with pulmonary hypertension by inhibiting the deposition of collagen.</p>

Effects of compound Salvia injection on number and activity of endothelial progenitor cells / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the effects of Compound Salvia injection (CSI) on the number and activity of endothelial progenitor cells (EPCs).</p><p><b>METHOD</b>Mononuclear fraction of human umbilical cord blood was obtained by density gradient centrifugation and plated on fibronectin coated culture dishes. Cells were divided in to five groups: group control, group VEGF, group CSI 50, group CSI 10 and group CSI 2 (supplemented with none cytokine, VEGF 10 ng x mL(-1), CSI 50, 10, 2 microg x mL(-1), respectively). After six days in culture, cell clusters were viewed with an inverted microscope, fluorescence-activated cell sorting (FACS) analysis of PE-CD34 and FITC-VE-Cadherin was performed to detect number of EPCs, adhesion assay was performed by replating cells on fibronectin coated dishes, and then counting adherent cells.</p><p><b>RESULT</b>Numbers of EPCs of group VEGF, group CSI 10 and group CSI 2 were significantly increased as compared with those of group control ( P < 0.01, P < 0.05, P < 0.01, respectively), and numbers of EPCs of group CSI 2 were more than those of group CSI 10 and group V (P < 0.01). Compared with group control, number of EPCs of group CSI 50 was significantly decreased (P < 0.01). Compared with group control, numbers of clusters and adhesive EPCs of group CSI 10 and group CSI 2 were significantly increased, while those of group CSI 50 were significantly decreased.</p><p><b>CONCLUSION</b>Low concentration CSI can significantly promote EPCs augmentation and enhance its functional activity, while high concentration CSI significantly restrains it.</p>

Influences of perindopril on pulmonary vascular remodeling in normobaric hypoxia-hypercapnia rats / 中国临床药理学与治疗学

Aim To investigate the effects of perindopril, an angiotensin converting enzyme inhibitor, on mean pulmonary arterial pressure(mPAP) and pulmonary vascular remodeling.Methods Using the normobaric hypoxia-hypercapnia rat model,the changes of plasma angiotensin Ⅱ (Ang Ⅱ), mPAP and ultrastructure of pulmonary arteriolar wall were observed after administration of perindopril.Results The mPAP and AngⅡ were significantly greater and the ultrastructure of the small lung vessels had a more obvious change in the 4 weeks hypoxia-hypercapnia group than those in the control group.It was also found that perindopril decreased AngⅡ, declined mPAP and ameliorated vascular ultrastructure change.But the change of ultrastructure was similar in the 8 weeks hypoxia-hypercapnia group and perindopril treatment group.Conclusion It is suggested that chronic hypoxia-hypercapnia should induce the remodeling of pulmonary arteriolar structure via AngⅡ and that perindopril could ease pulmonary vascular remodeling in early stage.