Importance of the length of the myocardial sleeve in the superior vena cava in patients with atrial fibrillation.

BACKGROUND: Pulmonary vein (PV) antrum isolation (PVAI) has proven to be a useful strategy for radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) worldwide. However, non-PV foci, especially from the superior vena cava (SVC), play an important role in initiating and maintaining AF. METHODS: In all, 427 consecutive patients with non-valvular AF who were admitted to our hospitals to undergo RFCA of AF using an EnSite™ system were evaluated. The length from the top of the sinus node to the top of the myocardial sleeve of SVC (L-SVC), longer and shorter diameter of SVC of 1 cm above of junction of right atrium and SVC, and local activation time (LAT) of SVC were measured. Then, the SVC firing was evaluated by an intravenous administration of isoproterenol and adenosine triphosphate. RESULTS: L-SVC, longer and shorter diameter of SVC, and LAT of SVC were significantly longer in the SVC firing group than non-SVC firing group (P < .05). Moreover, in accordance with the L-SVC, the frequency of the SVC firing significantly increased (P < .001). A univariate analysis and multivariate statistical analysis revealed that L-SVC longer than 37.0 mm (odds ratio 6.39) and longer diameter of SVC (odds ratio 6.78) were independent risk factors for SVC firing in patients with AF who underwent RFCA of AF. CONCLUSIONS: In view of these findings, L-SVC longer than 37.0 mm longer diameter SVC longer than 17.0 mm may be one of the important predictors of SVC firing in patients with AF.

Radiofrequency catheter ablation of premature ventricular contractions from the mitral annulus in patients without structural heart disease.

INTRODUCTION: We previously reported the clinical benefits of radiofrequency catheter ablation (RFCA) of premature ventricular contractions (PVCs) from the right ventricular outflow tract or near the His-bundle, which can often deteriorate the clinical status. PVCs from the mitral valve (MA-PVCs) also often deteriorate the patients' clinical status. This study aimed to evaluate the effect of ablating MA-PVCs with RFCA from a trans-interatrial septal approach on the clinical status in symptomatic patients with frequent MA-PVCs without structural heart disease. METHODS: The frequency of PVCs per the total heart beats by 24-hours Holter monitoring and New York Heart Association (NYHA) functional class in 22 patients with MA-PVCs were evaluated before and 6 months after RFCA. RESULTS: Procedural success was achieved in 20 (91%) of 22 patients. Of the 22 patients, in 15 (68%) and 1 (5%) patient, a successful RFCA on the left ventricular side of the MA using the trans-interatrial septal approach and trans-coronary sinus approach was achieved. Interestingly, in four (18%) patients, a successful RFCA on the left atrial (LA) side of the MA using a trans-interatrial septal approach was achieved. Ablating MA-PVCs readily improved the NYHA functional class compared to that before. A ≥0.62 peak deflection index and ≤30 years old may be one of the important predictors of successfully ablated MA-PVCs from the LA side of the MA. CONCLUSIONS: RFCA produces clinical benefits in patients with MA-PVCs. Further, it may be necessary to initially consider a trans-interatrial septal approach to ablate these PVCs.

Evaluation of Coronary Artery Disease in Patients with Atrial Fibrillation by Cardiac Computed Tomography for Catheter Ablation: CADAF-CT Trial 2.

Objective We recently reported that routine cardiac computed tomography (CT) scans for radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) could steadily detect coronary artery lesions (CALs) and could accurately detect myocardial ischemia in 9% of patients with AF who underwent RFCA of AF. The aim of this study was to identify the independent risk factor (s) of myocardial ischemia in those patients. Methods Patient characteristics, blood test, CALs, Ordinal coronary calcium scoring (OCCS), and myocardial Ischemia (MI) were evaluated in 757 consecutive patients who underwent RFCA of AF. Results There were 685 and 72 patients without and with myocardial ischemia, respectively. A univariate analysis and multivariate statistical analysis revealed that a male gender (Odds ratio 2.11), a high number of co-existing coronary risk factors (NCCRF ≥3) (Odds ratio 2.03), an elevated brain natriuretic peptide level (BNP ≥100 pg/mL) (Odds ratio 3.37), an enlarged left atrial volume (≥90 mL) (Odds ratio 2.91), and a high OCCS (≥4) (Odds ratio 13.0) were independent risk factors of myocardial ischemia in patients undergoing RFCA of AF. Conclusion The high OCCS (≥4) by cardiac CT was the strongest independent risk factor of myocardial ischemia in those patients. However, physicians may be able to find the high risk patients of myocardial ischemia by evaluating a male gender, in the presence of a high NCCRF (≥3) and elevated BNP (≥100 pg/mL) without OCCS by cardiac CT in patients undergoing RFCA of AF.

Evaluation of coronary artery disease in patients with atrial fibrillation by cardiac computed tomography for catheter ablation: CADAF-CT trial.

Almost all institutions routinely perform cardiac computed tomography (CT) before radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) to evaluate the cardiac anatomy. The ideal timing of the CT image acquisition is different between for RFCA of AF and for evaluation of coronary artery lesions (CALs). Thus, the aim of this study was to assess whether 64- or 320-line routine cardiac CT scans before RFCA of AF could evaluate both coronary artery lesions and pulmonary veins (LA-PVs) anatomy at the timing of the image acquisition of the LA-PVs in patients with AF who underwent RFCA of AF. The CALs were evaluated in 606 consecutive patients who underwent RFCA of AF assessed by the ideal timing of the CT image acquisition for RFCA of AF, and myocardial ischemia (MI) was also evaluated in patients with severe coronary stenosis (≥ 50%) and unevaluable CALs due to their severe coronary calcification and banding artifact by additional examinations combined with exercise stress testing, 201Tl scintigraphy, and/or fractionated flow reserve measurements. This study revealed that, in patients with AF who underwent RFCA of AF, (1) both 64- and 320-line cardiac CT scans for RFCA of AF could evaluate CALs in 93% of those patients, (2) the prevalence of MI was 9%, (3) significant relationships between the CHADS2 score and prevalence of MI were observed (p = 0.003), and (4) the positive predict values of MI in patients with severe coronary stenosis (≥ 50%) and unevaluable CALs also significantly increased in accordance with the CHADS2 score (p = 0.003). The evaluation of CALs and MI by routine cardiac CT for RFCA of AF combined with the additional examinations may be one of the most feasible modalities for patients with AF.

Radiofrequency catheter ablation of premature ventricular contractions from near the His-bundle.

OBJECTIVE: This study aimed to investigate the effects of radiofrequency catheter ablation (RFCA) and clinical and electrophysiological characteristics in symptomatic patients with premature ventricular contractions (PVCs) from near the His-bundle (His-PVCs). METHODS: The patient characteristics, prevalence of complications with any life style related disease (ALSRD) including hypertension, dyslipidemia, or diabetes mellitus, and/or cardiovascular disease (CVD) including coronary artery disease, cerebrovascular disease, renal dysfunction, or cardiomyopathy, clinical status, frequency of PVCs evaluated by 24hour Holter monitoring, echocardiography including the left ventricular diastolic dysfunction (LVDD) parameters, and electrophysiological findings were evaluated in 14 consecutive symptomatic patients with His-PVCs. RESULTS: The prevalence of males, being elderly and/or slightly obese, current and/or history of smoking, ALSRD or CVD related complications, and LVDD probably resulting from ALSRD and/or CVD complications were higher in patients with His-PVCs. RFCA of His-PVCs steadily decreased the PVC frequency and improved the systolic function, LV dilation, and clinical status, but not the LVDD. There was a significant relationship between the accordance rate of the QRS polarity between sinus rhythm and His-PVCs and the distance between the successful ablation site and His-bundle. CONCLUSION: The analysis of the QRS duration and accordance rate of the QRS polarity between sinus rhythm and His-PVCs before the RFCA may help to determine the distance between the origin of the PVCs and His-bundle. Further, the appropriate ablation catheter may be selected during the RFCA procedure. Finally, RFCA may be one of the most effective, feasible, and safest therapies for symptomatic patients with His-PVCs.

Clinical benefits of deep sedation with a supraglottic airway while monitoring the bispectral index during catheter ablation of atrial fibrillation.

BACKGROUND: Pulmonary vein antrum isolation (PVAI) under sedation has proven to be a useful strategy for catheter ablation of atrial fibrillation (AF). METHODS: To evaluate the clinical benefits of respiratory management using supraglottic airways (SGAs) under deep sedation while monitoring the bispectral (BIS) index during the PVAI and the durations from admission to the catheterization room to starting the radiofrequency energy delivery (Time α), and from starting the radiofrequency energy delivery to completion of the PVAI (Time ß), X-ray time, frequency of dislocations of the three-dimensional maps (D3DM), procedure-related complications, and proportion of an AF-free rate 15 months after the PVAI (PAFFR) in patients who received deep sedation without SGAs (Group A: n=48) and those with SGAs (Group B: n=51) were evaluated. RESULTS: There were no significant differences in patient characteristics, Time α (77±3 versus 78±2 min; p=0.816), complications of cardiac tamponade (2% versus 2%; p=0.966), or PAFFR (81% versus 88%; p=0.313) between the two groups. However, the Time ß (84±4 versus 67±3; p=0.001), X-ray time (53±2 versus 34±2; p<0.001), and minor complications of nasal bleeding (25% versus 0%; p=0.001) were significantly shorter and lower in Group B than in Group A, in accordance with a reduction in the hypoxia (15% versus 0%; p=0.007) and D3DM (31% versus 8%; p=0.003). CONCLUSIONS: These results may demonstrate the clinical benefits of deep sedation with SGAs while monitoring the BIS index without any hypoxia during PVAI in patients with AF.

Inappropriate Sinus Tachycardia Diagnosed and Treated as Depression Successfully Treated by Radiofrequency Catheter Ablation.

We experienced a man in his 20s with inappropriate sinus tachycardia (IST) initially diagnosed and treated as depression who was steadily treated with radiofrequency catheter ablation (RFCA) using an EnSite™ system. The patient has remained well without any symptoms or medications, including antidepressants, for two years since the RFCA. To avoid missing IST and treating it as an emotional problem and/or mental illness such as depression, physicians - including cardiologists - should be aware of these conditions when examining patients with multiple and incapacitating complaints including palpitations and general fatigue and/or tachycardia, especially characterized by an elevated resting heart rate or a disproportionate increase in the heart rate with minimal exertion.

Anti-ischemic effects of fasudil, a specific Rho-kinase inhibitor, in patients with stable effort angina.

Epicardial coronary stenosis causes myocardial ischemia; however, the role of coronary microvessels is poorly understood in the pathogenesis of effort angina. We have previously demonstrated that Rho-kinase pathway is substantially involved in coronary arterial hyperconstriction in patients with vasospastic angina and those with microvascular angina. In the present study, we tested our hypothesis that Rho-kinase is involved in coronary microvascular constriction in patients with effort angina. Intracoronary administration of fasudil (300 microg/min for 15 min), a specific Rho-kinase inhibitor, significantly increased oxygen saturation in coronary sinus vein from 37 +/- 3% to 41 +/- 3% (P < 0.05) but not in six age-matched controls (from 42 +/- 3% to 43 +/- 3%, P = NS). Furthermore, the fasudil treatment significantly ameliorated pacing-induced myocardial ischemia in patients with effort angina (magnitudes of symptom: 1.5 +/- 0.6 to 0.6 +/- 0.4, P < 0.01; ischemic ST-segment depression, 1.8 +/- 0.3 to 1.0 +/- 0.2 mm, P < 0.01; percent lactate production, 50 +/- 17% to 0.4 +/- 7%, P < 0.01) without significant hemodynamic changes. These results provide the first evidence that Rho-kinase is substantially involved in coronary microvascular dysfunction associated with myocardial ischemia in patients with effort angina, suggesting that Rho-kinase can be a novel therapeutic target in ischemic heart disease.

Rho-kinase inhibitor improves increased vascular resistance and impaired vasodilation of the forearm in patients with heart failure.

BACKGROUND: Rho-kinase is suggested to have an important role in enhanced vasoconstriction in animal models of heart failure (HF). Patients with HF are characterized by increased vasoconstriction and reduced vasodilator responses to reactive hyperemia and exercise. The aim of the present study was to examine whether Rho-kinase is involved in the peripheral circulation abnormalities of HF in humans with the Rho-kinase inhibitor fasudil. METHODS AND RESULTS: Studies were performed in patients with HF (HF group, n=26) and an age-matched control group (n=26). Forearm blood flow was measured with a strain-gauge plethysmograph during intra-arterial infusion of graded doses of fasudil or sodium nitroprusside. Resting forearm vascular resistance (FVR) was significantly higher in the HF group than in the control group. The increase in forearm blood flow evoked by fasudil was significantly greater in the HF group than in the control group. The increased FVR was decreased by fasudil in the HF group toward the level of the control group. By contrast, FVR evoked by sodium nitroprusside was comparable between the 2 groups. Fasudil significantly augmented the impaired ischemic vasodilation during reactive hyperemia after arterial occlusion of the forearm in the HF group but not in the control group. Fasudil did not augment the increased FVR evoked by phenylephrine in the control group significantly. CONCLUSIONS: These results indicate that Rho-kinase is involved in increased FVR and impaired vasodilation of the forearm in patients with HF.

The incidence and risk factors of cholesterol embolization syndrome, a complication of cardiac catheterization: a prospective study.

BACKGROUND: Cholesterol embolization syndrome is a systemic disease caused by distal showering of cholesterol crystals after angiography, major vessel surgery, or thrombolysis. METHODS: We prospectively evaluated a total of 1,786 consecutive patients 40 years of age and older, who underwent left-heart catheterization at 11 participating hospitals. The diagnosis of CES was made when patients had peripheral cutaneous involvement (livedo reticularis, blue toe syndrome, and digital gangrene) or renal dysfunction. RESULTS: Twenty-five patients (1.4%) were diagnosed as having CES. Twelve patients (48%) had cutaneous signs, and 16 patients (64%) had renal insufficiency. Eosinophil counts were significantly higher in CES patients than in non-CES patients before and after cardiac catheterization. The in-hospital mortality rate was 16.0% (4 patients), which was significantly higher than that without CES (0.5%, p < 0.01). All four patients with CES who died after cardiac catheterization had progressive renal dysfunction. The incidence of CES increased in patients with atherosclerotic disease, hypertension, a history of smoking, and the elevation of baseline plasma C-reactive protein (CRP) by univariate analysis. The femoral approach did not increase the incidence, suggesting a possibility that the ascending aorta may be a potential embolic source. As an independent predictor of CES, multivariate regression analysis identified only the elevation of pre-procedural CRP levels (odds ratio 4.6, P = 0.01). CONCLUSIONS: Cholesterol embolization syndrome is a relatively rare but serious complication after cardiac catheterization. Elevated plasma levels of pre-procedural CRP are associated with subsequent CES in patients who undergo vascular procedures.

Rho-kinase inhibition with intracoronary fasudil prevents myocardial ischemia in patients with coronary microvascular spasm.

OBJECTIVES: We sought to determine whether a potent Rho-kinase inhibitor fasudil prevents the occurrence of myocardial ischemia in patients with microvascular angina attributable to coronary microvascular spasm. BACKGROUND: Effective treatment of patients with angina who have normal coronary arteriograms (microvascular angina) has not yet been established. Rho-kinase-mediated calcium sensitization of the myosin light chain in smooth muscle cells has been implicated as substantially contributing to vascular hyperconstriction. METHODS: We studied consecutive 18 patients with angina and normal epicardial coronaries in whom intracoronary acetylcholine (ACh) induced myocardial ischemia (ischemic electrocardiographic changes, myocardial lactate production, or both) without angiographically demonstrable epicardial coronary vasospasm. All patients underwent a second ACh challenge test after pretreatment with either saline (n = 5) or fasudil (4.5 mg intracoronarily, n = 13). RESULTS: Myocardial ischemia was reproducibly induced by ACh in the saline group. In contrast, 11 of the 13 patients pretreated with fasudil had no evidence of myocardial ischemia during the second infusion of ACh (p < 0.01). The lactate extraction ratio (median value [interquartile range]) during ACh infusion was improved by fasudil pretreatment, from -0.16 (-0.25 to 0.04) to 0.09 (0.05 to 0.18) (p = 0.0125). CONCLUSIONS: Fasudil ameliorated myocardial ischemia in patients who were most likely having coronary microvascular spasm. The inhibition of Rho-kinase may be a novel therapeutic strategy for this group of patients with microvascular angina.

Suppression of coronary artery spasm by the Rho-kinase inhibitor fasudil in patients with vasospastic angina.

BACKGROUND: Increased activity of Rho-kinase causes hypercontraction of vascular smooth muscle and has been implicated as playing a pathogenetic role in divergent cardiovascular diseases such as coronary artery spasm. We examined whether an intracoronary infusion of fasudil, a selective Rho-kinase inhibitor, would attenuate coronary vasoconstrictor responses to acetylcholine (ACh) in patients with vasospastic angina. METHODS AND RESULTS: We studied 20 consecutive patients in whom coronary artery spasm was provoked by intracoronary ACh. The patients underwent a second ACh challenge after pretreatment with intracoronary saline (n=5) or fasudil (n=15; 300 microg/min for 15 minutes). Angina and coronary vasospasm were reproducibly induced by the second testing in patients who received saline. In contrast, fasudil markedly attenuated the coronary constriction induced by ACh (P<0.001) and prevented the occurrence of chest pain and ischemic ECG changes in all treated patients (both P<0.01 versus saline). Fasudil, at the dose used in this study, did not significantly change systemic hemodynamics or baseline coronary blood flow. CONCLUSIONS: Fasudil was effective in preventing ACh-induced coronary artery spasm and resultant myocardial ischemia in patients with vasospastic angina. We suggest that this Rho-kinase inhibitor may be a novel therapeutic intervention to treat ischemic coronary syndromes caused by coronary artery spasm.