Consecutive electrocardiographic changes during percutaneous coronary intervention for acute coronary syndrome with high-grade atrioventricular block: a case report.

BACKGROUND: Acute coronary syndrome (ACS) with high-grade atrioventricular block (HAVB) still has a poor mortality risk, even in the current percutaneous coronary intervention (PCI) era. However, early PCI for ACS with HAVB is associated with improved in-hospital survival and a 6-month survival similar to that of ACS without HAVB. CASE PRESENTATION: A 70-year-old man was admitted to our hospital for ACS with HAVB. ECG showed complete AV block, complete right bundle branch block (CRBBB), and left axis deviation. Cardiac enzymes were elevated. He underwent temporary pacemaker insertion and coronary angiography, which showed severe stenosis of the proximal right coronary artery (RCA), 99% stenosis of the distal RCA with Thrombolysis in Myocardial Infarction (TIMI) grade 2 flow, and total occlusion of the proximal left anterior descending artery (LAD). We performed primary PCI in both the RCA and LAD, which resulted in TIMI grade 3 flow in both. After PCI, the HAVB recovered to normal sinus rhythm with CRBBB; a normal QRS interval returned within three days. The patient was discharged from the hospital without complications. CONCLUSION: In this case of ACS with HAVB, early intensive coronary artery reperfusion resulted in long-term patient survival. The blood supply to the AV node and bilateral bundle branches is complex. Multivessel ischemia may compromise both primary and collateral blood flows to the AV node and septum, resulting in severe conduction impairment. Clinicians performing PCI should be aware of this anatomy and physiology.

The potential hazard of drug-eluting stent-induced coronary vasospasm causing subacute stent thrombosis: a case report.

BACKGROUND: Drug-eluting stent (DES) -induced coronary vasospasm is a well known phenomenon after stent implantation; however, the extent of this risk is still unknown. We report a case in which DES-induced severe coronary vasospasm was clinically suspected as a cause of subacute stent thrombosis (ST). CASE PRESENTATION: A 67-year-old man came to our hospital due to chest pain with mild exercise. He was diagnosed with effort angina by coronary angiography and underwent DES implantation in the mid-left ascending artery (LAD) after the administration of dual anti-platelet therapy. The procedure was uneventful, but his symptoms changed from effort angina to rest angina after stenting. Five days after the procedure, subacute ST occurred, requiring aspiration thrombectomy and balloon angioplasty. Thereafter, he continued to report early morning chest discomfort. We performed a spasm provocation test to evaluate the coronary vasomotor response; it revealed severe stent-edge spasm in the left main trunk to the LAD, except for the stented lesion, and total occlusion of the left circumflex artery. CONCLUSIONS: To our knowledge, the present case is the first report describing in-stent thrombosis secondary to stent-edge spasm. This case describes the potential hazard of DES-induced coronary vasospasm. Although there are several overlapping risk factors for ST development, we consider that stent-edge spasm also plays an important role in ST development. Therefore, we should monitor new-onset rest angina after stent implantation and carefully assess DES-induced coronary vasospasm.

Acute myocardial infarction with "wrap around" right coronary artery mimicking Takotsubo cardiomyopathy: a case report.

BACKGROUND: Takotsubo cardiomyopathy (TC) is a cardiomyopathy that shows distinctive clinical conditions first described more than 20 years ago. Because clinical features of TC mimic those of anterior acute myocardial infarction (AMI), the differential diagnosis is important in selecting the appropriate treatment strategy in the acute phase. But it was difficult to differentiate those two diseases because the TC-like findings; such as the electrocardiogram (ECG) changes and left ventricular wall motion abnormality can occur in AMI especially with the anatomical variance of the coronary artery. CASE PRESENTATION: A 63-year-old man was admitted due to sudden onset of chest pain and was in a cardiogenic shock state. His ECG showed ST-segment elevation in precordial (V2-6) and inferior leads (II, III, and aVF) and ST-segment depression in lead aVR. Blood biochemistry showed that cardiac enzymes were not elevated. Ultrasonic cardiography showed that the left ventricular apical level was akinetic, papillary muscle level was severely hypokinetic, and basal level was hyperkinetic, mimicking TC. However, coronary angiogram showed total occlusion of his right coronary artery wrapping around the cardiac apex. Successful percutaneous coronary intervention reversed his critical status. CONCLUSION: To our knowledge, the present case is the first report described AMI with wrap-around RCA, mimicking TC. Although TC is increasingly recognized as a true but relatively infrequent clinical entity, it is still important to carefully rule out obstructive coronary artery disease.

Evaluation of R-wave offset in the left chest leads for estimating the left ventricular activation delay: An evaluation based on coronary sinus electrograms and the 12-lead electrocardiogram.

BACKGROUND: The QRS duration does not always reflect the left ventricular (LV) activation delay in patients with ventricular conduction disturbances. The R-wave offset in left chest leads may more closely reflect the LV activation delay than the QRS offset. METHODS: We evaluated 138 cases with left bundle branch block (LBBB, n=11), right BBB (RBBB, n=38), non-specific intraventricular conduction disturbance (n=11), narrow QRS (<120ms, n=56) and right ventricular pacing (n=22). Cases with right axis deviation (120 to 270 degrees) were excluded. The intervals from the QRS onset to the V-waves in coronary sinus bipolar electrograms (QCS) were measured, and the longest interval was defined as the QCSmax. In the 12-lead electrocardiogram, the interval from the QRS onset to the R-wave offset (QR) was measured and then averaged in leads I-aVL, II-III-aVF, V1-V2, V3-V4 and V5-V6. RESULTS: Significant correlations (p<0.05) were found between QCSmax and QR in I-aVL (r=0.83), II-III-aVF (r=0.51) and V5-V6 (r=0.86) in cases with a normal axis (0 to 90 degrees, n=64); and I-aVL (r=0.90), II-III-aVF (r=0.31) and V5-V6 (r=0.69) in cases with left axis deviation (-45 to -89 degrees, n=52). Overall, the QRS duration was also correlated with QCSmax (r=0.72, p<0.001); however, this correlation was weaker than the correlation between QCSmax and QR in I-aVL (r=0.89, p<0.001) due to disparities in RBBB (p<0.001). CONCLUSIONS: The interval from the QRS onset to R-wave offset in the left chest leads reflects the degree of LV activation delay regardless of differences in QRS duration and morphology.

The potential hazard of a non-slip element balloon causing distal longitudinal stent deformation: the first clinical experience and in vitro assessment.

BACKGROUND: A new complication, longitudinal stent deformation (LSD), is increasingly reported with recent intracoronary stent designs. There have been experiences of unusual cases of distal LSD caused by entrapment of a Lacrosse® non-slip element (NSE) balloon (Goodman Co., Ltd., Nagoya, Japan), which has three flexible nylon elements to prevent slippage. Accordingly, the aim of this study is to report the clinical experience of distal LSD caused by the NSE in the documented center and to investigate the incidence and mechanisms involved. METHODS: Coronary intervention cases were retrospectively reviewed using the NSE balloon in hospital between May 2014 and June 2017. In bench testing, distal LSD was reproduced in a silicon tube model to identify its mechanism. RESULTS: A total of 95 patients with 107 lesions underwent coronary interventions with NSE. Of these, 72 lesions (12 de-novo lesions and 60 in-stent restenosis) were treated using in-stent dilatation. Two distal LSD cases occurred, representing an incidence of 2.78% (2/72) among all procedures; 16.7% (2/12) of the de-novo lesions developed LSD. In vitro experimentation allowed indentification of the mechanisms involved and bailout strategies. CONCLUSIONS: This is the first study to evaluate NSE balloon catheter entrapment complicated by distal LSD in which reconstruction of the deformed stent and retrieval of the NSE could be achieved successfully. There is a potential hazard for distal LSD during post-dilatation using the NSE balloon due to its structural characteristics. Careful assessment is needed to prevent this complication.

The effectiveness of super-selective injection with anchor balloon technique for collateral channel assessment.

The careful assessment of collateral channels is important for a retrograde approach for a chronic total coronary occlusion (CTO). This case report describes a percutaneous coronary intervention for CTO of the distal right coronary artery with good collateral circulation. All visible collateral channels failed by the retrograde approach; however, the procedure was successful using the distal atrial circumflex (AC) channel. Although this distal channel was poorly visualized on standard coronary angiography, it was clearly contrasted retrogradely from the CTO exit using a super-selective injection through the proximal AC channel as the antegrade flow was obstructed by the anchor balloon. This case highlights a unique super-selective injection with anchor balloon technique for collateral channel assessment.

Infective Endocarditis Associated with Streptococcal Toxic Shock Syndrome due to Streptococcus dysgalactiae subsp. equisimilis Infection in a Hemodialysis Patient.

The risk of infective endocarditis in chronic hemodialysis patients is markedly higher than that in the general population. We report the first case of a hemodialysis patient with infective endocarditis caused by Streptococcus dysgalactiae subsp. equisimilis (SDSE) who presented with streptococcal toxic shock syndrome. In the last decade, there has been an increase in the incidence of SDSE infections. Therefore, it is important to recognize SDSE as a possible causative agent of infective endocarditis in an immunocompromised population, such as hemodialysis patients.

Clinical significance of induced left atrial macro-reentrant tachycardia after pulmonary vein isolation.

BACKGROUND: The clinical significance of induced left atrial macro-reentrant tachycardia (LA-AT) after encircling pulmonary vein isolation (EPVI) is unclear. Our objective was to determine whether induced LA-ATs are associated with the clinical recurrence of ATs. METHODS: We studied 185 consecutive patients with paroxysmal atrial fibrillation (PAF) who underwent their first EPVI with an 8-mm tip, nonirrigated catheter approach. AT was induced by atrial burst pacing after the completion of EPVI, and the atrial activation pattern was evaluated using EnSite NavX. Induced LA-ATs were ablated only in patients with clinical ATs of suspected LA origin. The factors associated with occurrence of AT after the procedure were examined. RESULTS: LA-ATs were induced in 38 patients and ablated in 5 patients. During a follow-up of 23 ± 7 months, the occurrence of AT did not differ between patients with nonablated LA-ATs (4/33, 12 %) and those without any inducible ATs (16/113, 14 %, p > 0.99). In multivariate analysis, the number of ablation points for completing EPVI was the only independent predictor of AT occurrence (odds ratio 1.07, p < 0.01). A repeat procedure was performed in 22 of 26 patients who developed AT. Nineteen patients became free from AT and AF after ablation of the conduction gaps (EPVI, n = 17; another line, n = 4), extra PV firing (n = 4), focal AT (n = 4), and induced LA-ATs (n = 3). CONCLUSIONS: In patients who had EPVI for PAF using an 8-mm tip, nonirrigated catheter, the occurrence of AT after EPVI was mainly due to conduction gaps in the ablation line or extra PV triggers. In patients with PAF, LA-ATs induced during the first procedure did not require ablation if they were not associated with clinical AT.

Success rate of implantation and mid-term outcomes of the sirolimus-eluting stent.

BACKGROUND: The sirolimus-eluting stent (SES) is currently the sole drug-coated stent approved for use in Japan, but there are few reports on its safety and outcomes in Japan. METHODS AND RESULTS: From May 2004 to February 2005, a total of 297 patients with 402 lesions were treated with SES at 6 hospitals in the Kansai district. Follow-up angiography was performed in 82% of the patients and 80% of the lesions at 182+/-35 days after stenting. Coronary stenosis was evaluated using quantitative coronary angiography. Clinical and angiographic data were analyzed. Minimum lesion diameter was 0.75+/-0.52 mm and the reference diameter was 2.81+/-0.47 mm before stenting. The SES successfully dilated 99.5% of the lesions with few major adverse cardiac events. Restenosis occurred in 4.0% and the target lesion revascularization rate was 3.7%. Restenosis correlated with chronic hemodialysis, calcification, occlusion, ostial lesions, lesions kinked>45 degrees, right coronary artery (RCA) lesions and lesions at the ostium of the RCA. CONCLUSION: SES demonstrated a high rate of successful implantation with few complications, and mid-term outcomes were excellent. Patients with lesions at the ostium of the RCA or under chronic hemodialysis developed restenosis.