Impedance drop determines ablation lesion volume at the same level of ablation index

New parameters such as ablation index (AI) have been developed to create reliable ablation lesions. This study was performed to evaluate whether RF energy delivery with the same ablation index creates the similar ablation lesion volume. Ablation lesions were created in 5 pig hearts at ex-vivo state. Ablation was performed using an external-irri‑ gation contact-force sensing catheter on the epicardial side of the left ventricle with 90-degree of angle. RF ablation time was adjusted for targeting AI 600 at 8 different conditions. Lesion volume created with 0–5 g of contact force at 20 W was significantly lower than that of 11–20 g at 40W despite of the same AI (125 ± 76.2 vs. 272 ± 49.5 ­mm 3

Differentiation of the right versus left outflow tract ventricular arrhythmias using local activation time at the His bundle electrogram

Background@#Although multiple algorithms based on surface electrocardiographic criteria have been introduced to localize idiopathic ventricular arrhythmia (VA) origins from the outflow tract (OT), their diagnostic accuracy and clini‑ cal usefulness remain limited. We evaluated whether local activation time of the His bundle region could differentiate left and right ventricular OT VA origins in the early stage of electrophysiology study. @*Methods@#We studied 30 patients who underwent catheter ablation for OT VAs with a left bundle branch block pat‑ tern and inferior axis QRS morphology. The interval between the local V signal on the mapping catheter placed in the RVOT and His bundle region (V(RVOT)-V(HB) interval) and the interval from QRS complex onset to the local V signal on the His bundle region (QRS-V(HB) interval) were measured during VAs. @*Results@#The V(RVOT)-V(HB) and QRS-V(HB) intervals were significantly shorter in patients with LVOT VAs. The area under the curve (AUC) for the V(RVOT)-V(HB) interval by receiver operating characteristic analysis was 0.865. A cutoff value of ≤ 50 ms predicted an LVOT origin of VA with sensitivity, specificity, and positive and negative predictive values of 100%, 62.5%, 40%, and 100%, respectively. The QRS-V(HB) interval showed similar diagnostic accuracy (AUC, 0.840), and a cutoff value of ≤ 15 ms predicted an LVOT origin of VA with a sensitivity, specificity, and positive and negative predictive values of 100%, 70.8%, 45.2%, and 100%, respectively. @*Conclusion@#The V(RVOT)-V(HB) and QRS-V(HB) intervals could differentiate left from right OT origins of VA with high sensitivity and negative predictive values.

Differentiation of the right versus left outflow tract ventricular arrhythmias using local activation time at the His bundle electrogram

Background@#Although multiple algorithms based on surface electrocardiographic criteria have been introduced to localize idiopathic ventricular arrhythmia (VA) origins from the outflow tract (OT), their diagnostic accuracy and clini‑ cal usefulness remain limited. We evaluated whether local activation time of the His bundle region could differentiate left and right ventricular OT VA origins in the early stage of electrophysiology study. @*Methods@#We studied 30 patients who underwent catheter ablation for OT VAs with a left bundle branch block pat‑ tern and inferior axis QRS morphology. The interval between the local V signal on the mapping catheter placed in the RVOT and His bundle region (V(RVOT)-V(HB) interval) and the interval from QRS complex onset to the local V signal on the His bundle region (QRS-V(HB) interval) were measured during VAs. @*Results@#The V(RVOT)-V(HB) and QRS-V(HB) intervals were significantly shorter in patients with LVOT VAs. The area under the curve (AUC) for the V(RVOT)-V(HB) interval by receiver operating characteristic analysis was 0.865. A cutoff value of ≤ 50 ms predicted an LVOT origin of VA with sensitivity, specificity, and positive and negative predictive values of 100%, 62.5%, 40%, and 100%, respectively. The QRS-V(HB) interval showed similar diagnostic accuracy (AUC, 0.840), and a cutoff value of ≤ 15 ms predicted an LVOT origin of VA with a sensitivity, specificity, and positive and negative predictive values of 100%, 70.8%, 45.2%, and 100%, respectively. @*Conclusion@#The V(RVOT)-V(HB) and QRS-V(HB) intervals could differentiate left from right OT origins of VA with high sensitivity and negative predictive values.

A Genetic Risk Score for Atrial Fibrillation Predicts the Response to Catheter Ablation

BACKGROUND AND OBJECTIVES@#The association of susceptibility loci for atrial fibrillation (AF) with AF recurrence after ablation has been reported, although with controversial results. In this prospective cohort analysis, we aimed to investigate whether a genetic risk score (GRS) can predict the rhythm outcomes after catheter ablation of AF.@*METHODS@#We determined the association between 20 AF-susceptible single nucleotide polymorphisms (SNPs) and AF recurrence after catheter ablation in 746 patients (74% males; age, 59±11 years; 56% paroxysmal AF). A GRS was calculated by summing the unweighted numbers of risk alleles of selected SNPs. A Cox proportional hazard model was used to identify the association between the GRS and risk of AF recurrence after catheter ablation.@*RESULTS@#AF recurrences after catheter ablation occurred in 168 (22.5%) subjects with a median follow-up of 23 months. The GRS was calculated using 5 SNPs (rs1448818, rs2200733, rs6843082, rs6838973 at chromosome 4q25 [PITX2] and rs2106261 at chromosome 16q22 [ZFHX3]), which showed modest associations with AF recurrence. The GRS was significantly associated with AF recurrence (hazard ratio [HR] per each score, 1.13; 95% confidence interval [CI], 1.03–1.24). Patients with intermediate (GRS 4–6) and high risks (GRS 7–10) showed HRs of 2.00 (95% CI, 0.99–4.04) and 2.66 (95% CI, 1.32–5.37), respectively, compared to patients with low risk (GRS 0–3).@*CONCLUSIONS@#Our novel GRS using 5 AF-susceptible SNPs was strongly associated with AF recurrence after catheter ablation in Korean population, beyond clinical risk factors. Further efforts are warranted to construct a generalizable, robust genetic prediction model which can guide the optimal treatment strategies.

A Genetic Risk Score for Atrial Fibrillation Predicts the Response to Catheter Ablation

BACKGROUND AND OBJECTIVES: The association of susceptibility loci for atrial fibrillation (AF) with AF recurrence after ablation has been reported, although with controversial results. In this prospective cohort analysis, we aimed to investigate whether a genetic risk score (GRS) can predict the rhythm outcomes after catheter ablation of AF. METHODS: We determined the association between 20 AF-susceptible single nucleotide polymorphisms (SNPs) and AF recurrence after catheter ablation in 746 patients (74% males; age, 59±11 years; 56% paroxysmal AF). A GRS was calculated by summing the unweighted numbers of risk alleles of selected SNPs. A Cox proportional hazard model was used to identify the association between the GRS and risk of AF recurrence after catheter ablation. RESULTS: AF recurrences after catheter ablation occurred in 168 (22.5%) subjects with a median follow-up of 23 months. The GRS was calculated using 5 SNPs (rs1448818, rs2200733, rs6843082, rs6838973 at chromosome 4q25 [PITX2] and rs2106261 at chromosome 16q22 [ZFHX3]), which showed modest associations with AF recurrence. The GRS was significantly associated with AF recurrence (hazard ratio [HR] per each score, 1.13; 95% confidence interval [CI], 1.03–1.24). Patients with intermediate (GRS 4–6) and high risks (GRS 7–10) showed HRs of 2.00 (95% CI, 0.99–4.04) and 2.66 (95% CI, 1.32–5.37), respectively, compared to patients with low risk (GRS 0–3). CONCLUSIONS: Our novel GRS using 5 AF-susceptible SNPs was strongly associated with AF recurrence after catheter ablation in Korean population, beyond clinical risk factors. Further efforts are warranted to construct a generalizable, robust genetic prediction model which can guide the optimal treatment strategies.

Clinical Characteristics and Outcome of Acute Heart Failure in Korea: Results from the Korean Acute Heart Failure Registry (KorAHF)

BACKGROUND AND OBJECTIVES: The burden of heart failure has increased in Korea. This registry aims to evaluate demographics, clinical characteristics, management, and long-term outcomes in patients hospitalized for acute heart failure (AHF). SUBJECTS AND METHODS: We prospectively enrolled a total of 5625 consecutive subjects hospitalized for AHF in one of 10 tertiary university hospitals from March 2011 to February 2014. Descriptive statistics were used to determine the baseline characteristics of the study population and to compare them with those from other registries. RESULTS: The mean age was 68.5±14.5 years, 53.2% were male, and 52.2% had de novo heart failure. The mean systolic and diastolic blood pressures were 131.2±30.3 mmHg and 78.6±18.8 mmHg at admission, respectively. The left ventricular ejection fraction was ≤40% in 60.5% of patients. Ischemia was the most frequent etiology (37.6%) and aggravating factor (26.3%). Angiotensin converting enzyme inhibitors/angiotensin receptor blockers, beta-blockers, and aldosterone antagonists were prescribed in 68.8%, 52.2%, and 46.6% of the patients at discharge, respectively. Compared with the previous registry performed in Korea a decade ago, extracorporeal membrane oxygenation (ECMO) and heart transplantation have been performed more frequently (ECMO 0.8% vs. 2.8%, heart transplantation 0.3% vs. 1.2%), and in-hospital mortality decreased from 7.6% to 4.8%. However, the total cost of hospital care increased by 40%, and one-year follow-up mortality remained high. CONCLUSION: While the quality of acute clinical care and AHF-related outcomes have improved over the last decade, the long-term prognosis of heart failure is still poor in Korea. Therefore, additional research is needed to improve long-term outcomes and implement cost-effective care.

Development of a Rabbit Model for a Preclinical Comparison of Coronary Stent Types In-Vivo

Along with the development of innovative stent designs, preclinical trials in animal models are essential. Many animal models have been used and appear to yield comparable results to clinical trials despite substantial criticisms about their validity. Among the animal models, porcine coronary artery models have been the standard models for the preclinical evaluation of endovascular devices. However, rapid growth rate, high body weight potential, and the propensity to develop granulomatous inflammatory reactions are major limitations of the porcine coronary artery model. Compared with porcine coronary artery models, the comparative rabbit iliac artery model has the advantages of being small and easy to handle and relatively inexpensive. Furthermore, the rabbit model has been known to reliably reflect human restenosis histopathologically and have major advantages such as pairwise comparison, which makes each animal serve as its own control subject, therefore, maximizing its statistical power for comparative testing. However, despite the widespread use of this model, a systematic description of the procedure and harvest protocols has never been published. This article describes the surgical procedure, stent implantation procedure, method for tissue harvesting, and how measurements are performed. Although the results of animal models may not perfectly extrapolate to humans, the comparative rabbit iliac artery model may be a useful tool for assessing and comparing the efficacy of new coronary stents with conventional stent systems. This thorough description of the techniques required for vascular access, stent implantation, tissue preparation, and measurement, should aid investigators wishing to begin using the comparative rabbit iliac artery model.

Recurrent Syncope Triggered by Temporal Lobe Epilepsy: Ictal Bradycardia Syndrome

Ictal asystole is potentially lethal, and known to originate from the involvement of limbic autonomic regions. Appropriate treatment must include an antiepileptic drug and the implantation of a pacemaker. We report the case of a 54-year-old male with recurrent syncope secondary to ictal asystole triggered by temporal lobe epilepsy. This was confirmed by combined Holter and video-electroencephalogram monitoring.

First Isolation of Segniliparus rugosus from a Patient with Radiologic Features Similar to Non-Tuberculous Mycobacteriosis / 결핵및호흡기질환

In 2005, a group of mycolic acid-containing bacteria was characterized as belonging to a novel genus, Segniliparus with species Segniliparus rugosus and S. rotundus. We report a case of the S. rugosus isolated from a 54-year-old woman with radiologic features mimicking that of non-tuberculous mycobacteriosis (NTM). When the patient first visited our hospital, an acid-fast bacteria (AFB) smear tested positive and Mycobacterium tuberculosis polymerase chain reaction (TB PCR) was negative in the bronchoalveolar lavage sample. After 2 months, the growing colonies were reported as NTM, but could not be identified because they had died. One year after the initial visit, induced sputum samples showed the same results, positive AFB smear and negative TB PCR. At this point, the growing colonies were identified as S. rugosus. Therefore, we should consider Segniliparus genus as a differential diagnosis for AFB in respiratory specimens in addition to the genus Mycobacterium.

Importance of Clinical and Echocardiographic Hemodynamic Assessment in Chronic Pulmonary Embolism

We describe a 42-year-old man presenting to the emergency department with cardiogenic shock. He had a prior history of acute pulmonary embolism (PE), and had been on anticoagulation for 2 years. Although computed tomographic pulmonary angiography performed at the emergency department showed no change in the extent of PE and did not support a role of surgical treatment, pulmonary embolectomy was recommended by attending physician based on clinical and echocardiographic hemodynamic findings like unstable vital sign and markedly enlarged right ventricle with severely depressed systolic function. Surgery confirmed the presence of fresh thrombi. After surgery, hemodynamic status was progressively improved, but the patient died due to pneumonia and pulmonary hemorrhage.