Hiroshi Hoshizaki

Simple electrocardiographic criteria for identifying the site of origin of focal right atrial tachycardia.

To construct an algorithm for identifying the precise site of origin of focal right atrial tachycardia (RAT), we analyzed the P wave configuration in 32 patients with RAT who underwent successful radiofrequency catheter ablation. The RA was divided into three areas in the left anterior oblique view: superolateral, inferolateral, and inferomedial. There were 17 RATs arising from the crista terminalis (CT‐AT), 12 from the tricuspid annulus (TA‐AT), and 3 from the septum away from the TA (Sep‐AT). A negative P wave in lead aVR identified CT‐AT with a sensitivity (sens) of 100% and a specificity (spec) of 93%. In CT‐ATs, positive P waves in the inferior leads differentiated superolateral AT from inferolateral A T with a sens of 86% and a spec of 100%. In any type of AT with inferomedial or inferolateral foci, the P wave deflections in at least one of the inferior leads was negative, and negative P waves in leads V5 and V6 identified inferomedial AT with a sens of 92% and a spec of 100%. In ATs near the apex of Kochs triangle, the P wave duration in the inferior leads was shorter than during sin us rhythm. Conclusions: (1) the P wave configuration in lead aVR can easily differentiate CT‐AT from TA‐AT and Sep‐AT; (2) the P wave configuration in the inferior leads helps to determine a superior versus inferior origin in any type of AT; (3) in inferior AT, the P wave polarity in leads V5 and V6 is useful in determining a lateral versus medial origin; (4) this algorithm can predict accurately the origin of AT.

Impact of lesion calcification on clinical and angiographic outcome after sirolimus-eluting stent implantation in real-world patients

BACKGROUND Previous studies have demonstrated similar efficacy of the drug-eluting stent (DES) in patients with and without calcified lesions. However, most of the randomized trials have excluded patients with severe calcified lesions. This study aimed to examine the impact of lesion calcium on clinical and angiographic outcome after sirolimus-eluting stent (SES) implantation in real-world patients. METHODS Consecutive 380 patients with 556 lesions treated with SES were enrolled. Lesions were divided into Calc lesions (moderate or sever calcification; 195 lesions) and non-Calc lesions (none or mild calcification; 361 lesions) according to the lesion calcium. Quantitative coronary angiography (QCA) parameters, binary restenosis rate (%restenosis), target lesion revascularization (TLR) rate, and major adverse cardiac events (MACE) during follow-up were compared between the two groups. All patients were contacted at 1, 6, and 12 months after the procedure. RESULTS Lesion success rate was similar in the two groups. %Restenosis (9.2% vs. 3.6%; P<.05) and TLR (7.3% vs. 2.8%; P<.05) were significantly higher in Calc lesions. Stent thrombosis was observed in 0.7% of overall lesions with no difference between the two groups. The MACE rate in Calc patients (13.8%) was significantly higher than in non-Calc patients (6.1%). By multivariate analysis, hemodialysis (HD) and requirement of rotational atherectomy (RA) were predictive factors of TLR in the Calc lesions. CONCLUSIONS Coronary lesions with calcification comprise a high-risk cohort and are associated with a higher TLR and binary restenosis rates in real-world patients treated with SES. Moreover, patients with calcified lesions and on HD are associated with higher MACE rate.

Diagnostic Use of Serum Deoxyribonuclease I Activity as a Novel Early-Phase Marker in Acute Myocardial Infarction

Background—The delayed release of serum cardiac markers such as creatine kinase isoenzyme MB and equivocal early electrocardiographic changes have hampered a diagnosis of acute myocardial infarction (AMI) in the early phase after its onset. Therefore, a reliable serum biochemical marker for the diagnosis of AMI in the very early phase is desirable. Methods and Results—Serum samples were collected from the patients with AMI, unstable angina pectoris, stable angina pectoris, and other diseases. Levels of serum deoxyribonuclease I (DNase I) activity in the patients were determined. An abrupt elevation of serum DNase I activity was observed within approximately 3 hours of the onset of symptoms in patients with AMI, with significantly higher activity levels (21.7±5.10 U/L) in this group compared with the other groups with unstable angina pectoris (10.4±4.41 U/L), angina pectoris (10.8±3.70 U/L), and other diseases (9.22±4.16 U/L). Levels of the DNase I activity in serum then exhibited a marked time-dependent decline within 12 hours and had returned to basal levels within 24 hours. Conclusions—We suggest that serum DNase I activity could be used as a new diagnostic marker for the early detection of AMI.

Sirolimus-Eluting Stent Versus Balloon Angioplasty for Sirolimus-Eluting Stent Restenosis: Insights From the j-Cypher Registry

Background— Optimal treatment strategies for restenosis of sirolimus-eluting stents (SES) have not been adequately addressed yet. Methods and Results— During the 3-year follow-up of 12 824 patients enrolled in the j-Cypher registry, 1456 lesions in 1298 patients underwent target-lesion revascularization (TLR). Excluding 362 lesions undergoing TLR for stent thrombosis or TLR using treatment modalities other than SES or balloon angioplasty (BA), 1094 lesions with SES-associated restenosis in 990 patients treated with either SES (537 lesions) or BA (557 lesions) constituted the study population for the analysis of recurrent TLR and stent thrombosis after the first TLR. Excluding 24 patients with both SES- and BA-treated lesions, 966 patients constituted the analysis set for the mortality outcome. Cumulative incidence of recurrent TLR in the SES-treated restenosis lesions was significantly lower than that in the BA-treated restenosis lesions (23.8% versus 37.7% at 2 years after the first TLR; P<0.0001). Among 33 baseline variables evaluated, only hemodialysis was identified to be the independent risk factor for recurrent TLR by a multivariable logistic regression analysis. After adjusting for confounders, repeated SES implantation was associated with a strong treatment effect in preventing recurrent TLR over BA (odds ratio, 0.44; 95% confidence interval, 0.32 to 0.61; P<0.0001). The 2-year mortality and stent thrombosis rates between the SES- and the BA-treated groups were 10.4% versus 10.8% (P=0.4) and 0.6% versus 0.6%, respectively. Conclusions— Repeated implantation of SES for SES-associated restenosis is more effective in preventing recurrent TLR than treatment with BA, without evidence of safety concerns.

Prevalence and Characteristics of Idiopathic Outflow Tract Tachycardia with QRS Alteration Following Catheter Ablation Requiring Additional Radiofrequency Ablation at a Different Point in the Outflow Tract

Subtle variations in QRS morphology occurs during idiopathic outflow tract ventricular tachycardia (OTVT), but no studies have clarified the prevalence and characteristics of the OTVT with altered QRS morphology following radiofrequency catheter ablation (RFA), which then require an additional RF application at a different portion of the outflow tract to abolish OTVT. Of 202 patients with a monomorphic VT or premature ventricular contraction (PVC) originating from the outflow tract, 6 (3%) showed changes in QRS morphology in the OTVT following RFA, requiring an additional RF application to the outflow tract at a different portion. In all six patients, RFA was applied for the first or second OTVT to a right or left ventricular endocardial site, with the other site being the left sinus of Valsalva. In each patient, OTVT before or after the changes in QRS morphology had characteristic ECG findings originating from a particular portion of the outflow tract. Changes in QRS morphology consistently included an increase or decrease in R wave amplitude in all inferior leads. Detailed continuous observation of QRS morphology in OTVT, especially R wave amplitude in inferior leads, is important for identifying changes of QRS morphology during catheter ablation. Mapping and ablation at a different portion of the outflow tract is then needed for cure.

Significance of two potentials for predicting successful catheter ablation from the left sinus of Valsalva for left ventricular epicardial tachycardia.

The aim of this study was to identify the characteristics of electrograms that may be helpful in predicting successful ablation of idiopathic ventricular tachycardia from the aortic sinus of Valsalva. Data were obtained from 23 patients with symptomatic ventricular tachycardia or premature ventricular contractions (LV‐VT) who underwent RF catheter ablation from the left sinus of Valsalva. Electrograms before and after application of RF energy during sinus rhythm and during LV‐VT were analyzed. Complete elimination of LV‐VT was finally achieved in 21 (91%) patients. The incidence of presystolic potentials preceding the QRS complex of LV‐VT (P1 potential) was 90% for the 21 successful ablation sites, which did not differ from the incidence for the 24 unsuccessful sites (79%; P = 0.5). During sinus rhythm, a potential following the QRS complex (P2 potential) was more often recorded at the successful ablation site than at an unsuccessful ablation site before and after application of RF energy (before, P < 0.05; after, P < 0.001). The appearance of the P2 potential or a delay in the preexisting P2 potential after application of RF energy was observed only at the successful ablation sites (P < 0.001). In 18 control individuals who had no LV‐VT, no P2 potential was recorded within the left sinus of Valsalva. Although the P1 potential may be useful for identifying the successful ablation site, its sensitivity is low. The appearance of the P2 potential or an increasingly delayed P2 potential after application of RF energy may be more useful than the P1 potential for predicting successful ablation.

Combined therapy with carvedilol and amiodarone is more effective in improving cardiac symptoms, function, and sympathetic nerve activity in patients with dilated cardiomyopathy: Comparison with carvedilol therapy alone

BackgroundCarvedilol therapy has been reported to be more effective than other beta-blockers in patients with chronic heart failure (CHF). Amiodarone is an anti-arrhythmic medicine that has also been reported to be effective in patients with CHF. But the usefulness of combined therapy with carvedilol and amiodarone has not been reported.MethodsWe compared 15 patients (M/F=3/12, age=57±8 y) with dilated cardiomyopathy (DCM) receiving carvedilol and amiodarone with 15 patients (M/F=3/12, age=61±9 y) receiving carvedilol alone. Patients were studied before and after 1 year of treatment (1Y). NYHA class and exercise capacity based on the specific-activity-scale (SAS), were assessed. Cardiac sympathetic nerve activity was estimated using total defect score (TDS), H/M ratio and washout rate (WR) of 123I-MIBG imaging. Cardiac function was evaluated using 99mTc-MIBI QGS.ResultsCombined, therapy improved several parameters much more than carvedilol alone (p<0.05) including delta-TDS (15.0±8.6 vs. 7.6±7.2) and delta- WR (15.9±11.0% vs. 7.3±10.0%) for 123I-MIBG imaging, delta-LVEF (26.1±11.4% vs. 15.5±13.8%), delta-endsystolic volume (100±63.8 ml vs. 58.9±47.3 ml), 1Y NYHA class (1.5±0.5 vs. 1.9±0.5), 1Y SAS (7.3±0.7 Mets vs. 6.2±1.0 Mets), and delta-SAS (3.4±0.8 Mets vs. 2.6±1.1 Mets).ConclusionCombined therapy with carvedilol and amiodarone is more effective in improving cardiac symptoms, exercise capacity, cardiac function and cardiac sympathetic nerve activity in patients with DCM.

Safety and Efficacy of Sirolimus-Eluting Stent Implantation in Patients With Acute Coronary Syndrome in the Real World

The use of drug-eluting stents in patients with acute coronary syndrome (ACS), particularly those with acute myocardial infarction (AMI), is controversial owing to concerns about late adverse events. We evaluated the long-term safety of sirolimus-eluting stent implantation in patients with ACS. Of 10,778 patients treated exclusively with a sirolimus-eluting stent in the j-Cypher registry, the 3-year outcomes of 2,308 patients with ACS (953 patients with AMI) were compared to those of 8,470 patients without ACS. Compared to patients without ACS, the patients with ACS had a significantly greater adjusted risk of death or myocardial infarction (hazard ratio [HR] 1.24, 95% confidence interval [CI] 1.12 to 1.37, p <0.0001) and definite or probable stent thrombosis (HR 1.43, 95% CI 1.11 to 1.82, p = 0.006) within the first year after sirolimus-eluting stent implantation. However, after 1 year, patients with ACS no longer had a greater risk of death or myocardial infarction (HR 1.01, 95% CI 0.90 to 1.13, p = 0.87) and stent thrombosis (HR 1.32, 95% CI 0.92 to 1.86, p = 0.13). Of the patients with ACS, those with AMI had a greater risk of death or myocardial infarction (HR 1.33, 95% CI 1.12 to 1.6, p = 0.001) and stent thrombosis (HR 1.57, 95% CI 1.05 to 2.39, p = 0.03) than those with unstable angina pectoris within the first year. However, they had a similar risk of death or myocardial infarction (HR 1.00, 95% CI 0.78 to 1.22, p = 0.83) and stent thrombosis (HR 0.83, 95% CI 0.38 to 1.6, p = 0.59) after 1 year. The risk of late adverse events >1 year after sirolimus-eluting stent implantation was similar between those with and without ACS and between those with AMI and those with unstable angina pectoris.

Selected Slow Pathway Ablation in a Patient with Corrected Transposition of the Great Arteries and Atrioventricular Nodal Reentrant Tachycardia

AVNRT in Corrected TGA. We report the first known case of AV nodal reentrant tachycardia (AVNRT) associated with a corrected transposition of the great arteries to be treated successfully by ablation of the slow pathway. Triple AV nodal pathways were observed in the anterograde direction and two types of AVNRT were induced. Input of the fast pathway to the AV node was located at the anterior portion of the left‐sided A V annulus, while the input of the intermediate and slow pathways was located at the anteroseptal portion of the right‐sided AV annulus. Radiofrequency energy ablation at the right anteroseptal site eliminated the intermediate and slow pathways.

Nicorandil administration shows cardioprotective effects in patients with poor TIMI and collateral flow as well as good flow after AMI

BackgroundNicorandil (NCR) has been reported to have cardioprotective effects in patients with AMI. And collateral flow and TIMI flow are also important determinants of final salvaged myocardium in patients with AMI. There is no evidence as to whether TIMI or collateral flow modifies the cardioprotective effects of NCR in patients with AMI.Methods and ResultsWe studied 68 initial AMI patients without restenosis which was defined as 50% diameter reduction of the intervention site in the chronic period. On initial CAG, 41 patients with poor flow (collateral: Rentrop 0 or 1 and TIMI 0 or 1) were NCR/Non-NCR = 20/21. Twenty-seven patients with good flow (collateral: Rentrop 2 or 3 or TIMI 2 or 3) were NCR/Non-NCR = 13/14. NCR was administered intravenously (4 mg) via intracoronary injection (2 mg) or continuously (4 mg/h).99mTc-tetrofosmin (TF) and123I-BMIPP SPECT were performed in the subacute and chronic (6 Mo) periods. In 20 SPECT segments, summed defect scores (TDS) and regional wall motion (WMS:-1 = dyskinesis ∼ 4 = normal) of AMI segments using TF-QGS were estimated. In poor flow patients, the following values for NCR patients were higher (p < 0.05) than for Non-NCR patients in the improvement degree of TDS (BMIPP) (NCR: 6.5 ± 3.9 vs. Non-NCR: 4.0 ± 3.4), the improvement degree of TDS (TF) (NCR: 5.7 ± 4.6 vs. Non-NCR: 2.2 ± 4.6), and delta WMS (NCR: 1.4 ± 1.1 vs. Non-NCR: 0.9 ± 1.0). In good flow patients, the following values for NCR patients were better (p < 0.05) than for Non-NCR patients in TDS (BMIPP) (subacute) (NCR: 9.9 ± 5.2 vs. Non-NCR: 16.5 ± 10.4) and (chronic) (NCR: 5.1 ± 5.2 vs. Non-NCR: 12.4 ± 8.5), WMS (subacute) (NCR: 1.7+1.3 vs. Non-NCR: 1.0 ± 1.0), and WMS (chronic) (NCR: 3.0 ± 1.5 vs. Non-NCR: 2.1 ± 1.3).ConclusionWe conclude that the cardioprotective effects of nicorandil administration are observable in both AMI patients with poor collateral and TIMI flow and good flow before reperfusion therapy.