Rhodiola Inhibits Atrial Arrhythmogenesis in a Heart Failure Model.

INTRODUCTION: Rhodiola, a popular plant in Tibet, has been proven to decrease arrhythmia. The aim of this study was to elucidate the molecular mechanism and electrophysiological properties of rhodiola in the suppression of atrial fibrillation. METHODS: This study consisted of 3 groups as follows: Group 1: normal control rabbits (n = 5); Group 2: rabbits with heart failure (HF) created by coronary ligation and who received 2 weeks of water orally as a placebo (n = 5); and Group 3: rabbits with HF who received 2 weeks of a rhodiola 270 mg/kg/day treatment orally (n = 5). The monophasic action potential, histology, and real-time polymerase chain reaction (RT-PCR) analysis of ionic channels and PI3K/AKT/eNOS were examined. RESULTS: Compared with the HF group, attenuated atrial fibrosis (35.4 ± 17.4% vs. 16.9 ± 8.4%, P = 0.05) and improved left ventricular (LV) ejection fraction (51.6 ± 3.4% vs. 68.0 ± 0.5%, P = 0.001) were observed in the rhodiola group. The rhodiola group had a shorter ERP (85.3 ± 6.8 vs. 94.3 ± 1.2, P = 0.002), APD90 (89.3 ± 1.5 vs. 112.7 ± 0.7, P < 0.001) in the left atrium (LA), and decreased AF inducibility (0.90 ± 0.04 vs. 0.42 ± 0.04, P < 0.001) compared with the HF group. The mRNA expressions of Kv1.4, Kv1.5, Kv4.3, KvLQT1, Cav1.2, and SERCA2a in the HF LA were up-regulated after rhodiola treatment. The rhodiola-treated HF LA demonstrated higher mRNA expression of PI3K-AKT compared with the HF group. CONCLUSIONS: Rhodiola reversed LA electrical remodeling, attenuated atrial fibrosis and suppressed AF in rabbits with HF. The beneficial electrophysiological effect of rhodiola may be related to upregulation of Kv1.4, Kv1.5, Kv4.3, KvLQT1, Cav1.2, SERCA2a, and activation of PI3K/AKT signaling.

Additive Value of Heart Rate Variability in Predicting Obstructive Coronary Artery Disease Beyond Framingham Risk.

BACKGROUND: Heart rate variability (HRV) is usually reduced in patients with CAD. We therefore investigated whether reduced HRV is predictive of angiographic CAD beyond Framingham risk in patients with stable angina. METHODS AND RESULTS: A total of 514 patients (age, 66.1 ± 14.3 years, 358 men) were enrolled. Holter ECG was performed before catheterization, and 24-h HRV was analyzed in both the frequency domain (VLF, LF, HF and total power) and the time domain (SDNN, SDANN, RMSSD and pNN20). Angiographic CAD was defined as ≥ 50% diameter reduction of 1 or more coronary arteries. On coronary angiography 203 patients (39.6%) had angiographic CAD. Patients with CAD had significantly higher Framingham risk and lower HRV according to both frequency and time domain parameters. After controlling for age, gender, heart rate, SBP, renal function, lipids and Framingham risk, reduced HRV indices remained predictors of CAD (OR, 95% CI for LF, HF, SDNN, RMSSD and pNN20: 0.81, 0.66-0.99; 0.77, 0.63-0.94; 0.75, 0.59-0.96; 0.72, 0.58-0.88; and 0.76, 0.62-0.94, respectively). On subgroup analysis, HRV parameters appeared to be predictive of CAD only in subjects with high Framingham risk or diabetes. CONCLUSIONS: Reduced HRV is predictive of CAD in patients with stable angina, independent of traditional risk factors and Framingham risk. The predictive value of HRV may be relevant only in subjects with high Framingham risk or diabetes.

2016 Guidelines of the Taiwan Heart Rhythm Society and the Taiwan Society of Cardiology for the management of atrial fibrillation.

Atrial fibrillation (AF) is the most common sustained arrhythmia. Both the incidence and prevalence of AF are increasing, and the burden of AF is becoming huge. Many innovative advances have emerged in the past decade for the diagnosis and management of AF, including a new scoring system for the prediction of stroke and bleeding events, the introduction of non-vitamin K antagonist oral anticoagulants and their special benefits in Asians, new rhythm- and rate-control concepts, optimal endpoints of rate control, upstream therapy, life-style modification to prevent AF recurrence, and new ablation techniques. The Taiwan Heart Rhythm Society and the Taiwan Society of Cardiology aimed to update the information and have appointed a jointed writing committee for new AF guidelines. The writing committee members comprehensively reviewed and summarized the literature, and completed the 2016 Guidelines of the Taiwan Heart Rhythm Society and the Taiwan Society of Cardiology for the Management of Atrial Fibrillation. This guideline presents the details of the updated recommendations, along with their background and rationale, focusing on data unique for Asians. The guidelines are not mandatory, and members of the writing committee fully realize that treatment of AF should be individualized. The physician's decision remains most important in AF management.

Association of Single Nucleotide Polymorphisms with Atrial Fibrillation and the Outcome after Catheter Ablation.

BACKGROUND: The association of gene variants with atrial fibrillation (AF) type and the recurrence of AF after catheter ablation in Taiwan is still unclear. In this study, we aimed to investigate the relationships between gene variants, AF type, and the recurrence of AF. METHODS: In our investigation, we examined 383 consecutive patients with AF (61.9 ± 14.0 years; 63% men); of these 383 patients, 189 underwent catheter ablation for drug-refractory AF. Thereafter, the single nucleotide polymorphisms rs2200733, and rs7193343 were genotyped using real-time polymerase chain reaction. RESULTS: The rs7193343 variant was independently associated with non-paroxysmal AF (non-PAF). In the PAF group, the rs7193343 variant was independently associated with AF recurrence after catheter ablation. However, the rs2200733 variant was not associated with AF recurrence in this group. The combination of the rs7193343 and rs2200733 risk alleles was associated with a better predictive power in the PAF patients. In contrast, in the non-PAF group, the SNPs were not associated with recurrence. The rs7193343 and rs2200733 variants were not associated with different atrial voltage and activation times. CONCLUSIONS: The rs7193343 variants were associated with AF recurrence after catheter ablation in PAF patients but not in non-PAF patients. The rs7193343 CC variant was independently associated with non-PAF.

Long-Term Follow-Up of Catheter Ablation of Ventricular Arrhythmias: Experiences from a Tertiary Referral Center in Taiwan.

BACKGROUND: Radiofrequency catheter ablation (RFCA) is an alternative therapeutic management for drug-refractory ventricular arrhythmias (VA). However, long-term follow-up of clinical outcome after RFCA for VAs in Taiwan remains unknown. METHODS: From 1999 to 2013, patients undergoing RFCA for VAs from a single referral center were consecutively enrolled. The annual distribution of cases, clinical characteristics, etiology, disease entity and electrophysiological studies were investigated. The clinical outcomes and recurrences between distinct entities were compared. RESULTS: A total of 502 patients receiving RFCA of VAs were eligible, including 388 patients for idiopathic VAs and 114 for substrate VAs. The annual distribution displayed a tendency towards a gradual increase in ablation cases within 2009-2013 compared with the prior decade (p < 0.001). Acute success was achieved in 453 patients (90.2%), partial success in 3 (0.6%), and failed ablation in 46 (9.2%). During a mean follow-up of 39.77 ± 48.75 months, 126 (25.1%) patients developed recurrences. Kaplan-Meier analysis demonstrated better prognosis after RFCA in patients with idiopathic fascicular VT and RVOT VAs (p < 0.001) and attenuation of the occurrences of sustained VT/VF, ICD therapies, and mortality in patients with BrS and ARVD/C (p = 0.036), as well as overall ICD interventions in substrate VAs (p < 0.001). CONCLUSIONS: RFCA could be an effective and alternative strategy in the elimination of idiopathic VAs and prevention of malignant events in substrate VAs at an experienced referral center in Taiwan. Distinct location of arrhythmogenic trigger and disease entities may result in non-uniform recurrences and prognosis. KEY WORDS: Idiopathic; Radiofrequency catheter ablation; Recurrence; Substrate; Ventricular arrhythmias.

Relationship between intrinsic cardiac autonomic ganglionated plexi and the atrial fibrillation nest.

BACKGROUND: Spectral analysis of the left atrium can identify high dominant frequency (DF) sites, which might play a role in the perpetuation of atrial fibrillation (AF). Furthermore, the role of the cardiac autonomic nervous system (CANS) in the genesis of AF has been demonstrated. The relationship between CANS and the high-DF sites (AF nest) was the aim of the investigation. METHODS AND RESULTS: In 12 dogs, high frequency stimulation was applied to locate 4 major left atrial (LA) ganglionated plexi (GPs). An Ensite Array and a mapping catheter were delivered into the left atrium for electroanatomical mapping. During sinus rhythm, spectral analysis was performed on the bipolar electrograms in the left atrium before and after epicardial GP ablation. The majority of AF nests were close to the GPs (52±18% of total AF nests). After GP ablation, the mean LA DF values decreased from 54±7Hz to 49±4Hz (P=0.023), and DF values of the AF nest decreased from 93±2Hz to 87±4Hz (P=0.001). Most of the previous AF nest sites close to the GPs disappeared (85±23%). The surface area of the AF nest decreased from 9±5cm(2) to 3±2cm(2) (P=0.001). CONCLUSIONS: Catheter ablation of the GP decreased the DF values, AF nest areas and diminished the number of AF nests; particularly those close to the GPs, indicating that the CANS might play an important role in the mechanism of the AF nest.

Incidence and risk of atrial fibrillation in sleep-disordered breathing without coexistent systemic disease.

BACKGROUND: Although the link between sleep-disordered breathing (SDB) and atrial fibrillation (AF) has been reported, a population-based longitudinal cohort study was lacking. The goal of the present study was to investigate the AF risk carried by SDB, using the National Health Insurance Research Database in Taiwan. METHODS AND RESULTS: From 2000 to 2001, a total of 579,521 patients who had no history of cardiac arrhythmias or significant comorbidities were identified. Among them, 4,082 subjects with the diagnosis of SDB were selected as the study group, and the remaining 575,439 subjects constituted the control group. The study endpoint was the occurrence of new-onset AF. During a follow-up of 9.2±2.0 years, there were 4,023 patients (0.7%) experiencing new-onset AF. The occurrence rate of AF was higher in patients with SDB compared to those without it (1.3% vs. 0.7%, P<0.001). The AF incidences were 1.38 and 0.76 per 1,000 person-years for patients with and without SDB, respectively. After anadjustment for age and sex, SDB was a significant risk factor of AF with a hazard ratio of 1.536. The AF risk increased with increasing clinical severity of SDB, represented by the requirement of continuous positive airway pressure use. CONCLUSIONS: SDB itself, without the coexistence of other systemic diseases, was a risk factor of AF.

Long-Term Prognosis in Recipients of Implantable Cardioverter-Defibrillators for Secondary Preventions in Taiwan - A Multicenter Registry Study.

BACKGROUND: The use of an implantable cardioverter-defibrillator (ICD) has a proven capacity to prevent sudden cardiac death (SCD), and can also improve survival duration in well-selected patients. The goal of the present study was to investigate the long-term prognosis and predictors of mortalities among ICD recipients in Taiwan. METHODS: From 1998 to 2009, 238 consecutive patients who experienced SCDs or life-threatening ventricular tachyarrhythmias without correctable causes and received ICD implantations in 3 medical centers (Taipei, Taichung and Kaohsiung Veterans General Hospital) were enrolled in this study. The clinical endpoint was defined as the occurrence of all-cause mortality during the follow-up. RESULTS: The mean age of the patients was 63.0 ± 15.3 years, and 76.5% of them were male. Ischemic cardiomyopathy was the leading cause for the ICD implantations (39.1%). During the mean follow-up duration of 36.8 ± 29.8 months, there were 48 patients (20.2%) who died. Patients with structural heart diseases had a higher mortality rate than those without such diseases. Additionally, old age, low left ventricular ejection fraction (LVEF) and a history of diabetes mellitus (DM) were significant predictors of mortality. The optimal cutoff values for age (70 years) and LVEF (40%) in predicting mortality were further identified using the receiver operating characteristic curves. CONCLUSIONS: Based on the ICD registry from 3 medical centers in Taiwan, the annual mortality rate was around 6.6% and was higher in those patients with structural heart diseases. We observed that old age, low LVEF and a history of DM were significant predictors of mortality. KEY WORDS: Implantable cardioverter-defibrillator; Mortality; Predictor; Taiwan.

Differences in the atrial electrophysiological properties between vagal and sympathetic types of atrial fibrillation.

INTRODUCTION: Autonomic modulation of the cardiac activity plays an important role in the pathogenesis of atrial fibrillation (AF). The aim of this study was to assess the differences in the atrial electrical and structural properties between patients with vagal and sympathetic AF. METHODS: The study included 30 patients (53 ± 12 years old, male 26) with frequent attacks of symptomatic paroxysmal AF. All cases underwent 24-hour ambulatory Holter monitoring before the catheter ablation. The onset of AF accompanied with an increased HF component and decreased L/H ratio was designated as a vagal type (group 1, n = 12), whereas a decreased HF component and increased L/H ratio was classified as a sympathetic type (group 2, n = 18). Electrical and structural properties were evaluated during the ablation procedure. RESULTS: All patients had AF originating from PVs. There was a higher incidence of non-PV triggers in group 2 patients than that in group 1 (44% vs 8%, P = 0.04). Group 1 had a higher bipolar peak-to-peak voltage and mean DF of the global left atrium (LA), shorter total activation time, and smaller LA volume than group 2, whereas the electrical and structural properties in the right atrium were similar. After a follow-up of 15 ± 7 months, there was a lower incidence of AF recurrence in group 1 than that in group 2 (0% vs 28%, P = 0.02). CONCLUSION: There are better electrical properties and a smaller LA volume in patients with vagal-type AF. In contrast, the LA substrate is worse, and coexisting non-PV triggers and recurrence following ablation are more prevalent in patients with the sympathetic-type AF.

Five-Year Outcomes after Acute Myocardial Infarction in Patients with and without Diabetes Mellitus in Taiwan, 1996-2005.

BACKGROUND: Diabetes mellitus (DM) is a strong risk factor of cardiovascular disease. To date, the impact of DM on outcomes after acute myocardial infarction (AMI) in Taiwan is undetermined. The aim of this study was to compare five-year outcomes after AMI in patients with and without diabetes in Taiwan. METHODS: A nationwide cohort of 25,028 diabetic and 56,028 non-diabetic patients who were first hospitalized with AMI between 1996 and 2005 was enrolled through linkage with the Taiwan National Health Insurance research database. Patient mortality rates within 30 days after AMI, and 1, 3, and 5 years thereafter were compared. RESULTS: Length of hospital stay (8.9 ± 8.7 vs. 8.2 ± 8.0 days, p < 0.01) and medical cost during admission (in Taiwan dollars: $129,123 ± $158,073 vs. $121,631 ± $157,018, p < 0.01) were significantly higher in diabetic patients. The difference in mortality rate within 30 days was insignificant between diabetic and non-diabetic patients (18.1% vs. 17.6%, p = 0.06). Mortalities within 1 year (31.0% vs. 26.8%, p < 0.01), 3 years (42.4% vs. 34.7%, p < 0.01), and 5 years (50.6% vs. 41.1%, p < 0.01) were significantly higher in diabetic patients. In patients with AMI who underwent percutaneous coronary intervention (PCI) during index admission, the mortality rate within 30 days was insignificant (6.3% vs. 6.4%, p = 0.70) but mortalities within 1 year (15.2% vs. 11.6%, p < 0.01), 3 years (24.1% vs. 17.2%, p < 0.01), and 5 years (32.2% vs. 22.6%, p < 0.01) were significantly higher in diabetic patients. CONCLUSIONS: The average patient length of hospital stay and medical cost during admission were significantly higher in diabetic patients. Additionally, the difference in mortality rate within 30 days after AMI was insignificant between diabetic and non-diabetic patients. Also, long-term mortality after AMI was significantly higher in diabetic patients. KEY WORDS: Acute myocardial infarction; Diabetes mellitus; Length of hospital stay; Medical cost; Mortality; National health insurance.

Chronic Kidney Disease, But Not Diabetes, Can Predict 30-Day Outcomes in Patients with ST-Elevation Myocardial Infarction after Primary Percutaneous Coronary Intervention: A Single-Center Experience.

BACKGROUND: Patients with acute coronary syndrome and impaired renal function have been shown to have high mortality. However, there is scarce literature to date addressing the impact of diabetes mellitus (DM) and renal function on clinical outcomes of ST elevation myocardial infarction (STEMI) in Taiwan. METHOD: This study enrolled 512 STEMI patients who received primary percutaneous coronary intervention. Patients were divided into 4 groups including group 1: patients without DM or CKD (nDM-nCKD); group 2: patients with DM but without CKD (DM-nCKD); group 3: patients with CKD but without DM (nDM-CKD); group 4: patients with DM and CKD (DM-CKD). Patients were also classified into four groups based on their estimated glomerular filtration rates (eGFR): stage 1 (eGFR ≥ 90 ml/min/1.73 m(2), n = 163), stage 2 (eGFR = 89-60 ml/min/1.73 m(2), n = 171), stage 3 (eGFR = 59-30 ml/min/1.73 m(2), n = 136), and stage 4 (eGFR < 30 ml/min/1.73 m(2), n = 42). The complication rates, length of hospital stay, and 30-day outcomes were analyzed. RESULTS: The patients in both the nDM-CKD group and DM-CKD group had higher incidences of hypotension, intra-aortic balloon counterpulsation use, and respiratory failure (p < 0.005). They had significantly longer hospital stay and 30-day mortality rates (p < 0.001). The patients with CKD stage 3 and 4 had longer hospital stay and higher 30-day mortality rates (p < 0.001). However, DM was not an independent factor on the length of hospital stay and 30-day mortality rates. CONCLUSIONS: STEMI patients with impaired renal function, but not DM, had significantly longer hospital stay and higher 30-day mortality rates. KEY WORDS: Chronic kidney disease; Diabetes mellitus; Mortality; Primary percutaneous coronary intervention; ST-segment elevation myocardial infarction.

The Effect of Intensified Low Density Lipoprotein Cholesterol Reduction on Recurrent Myocardial Infarction and Cardiovascular Mortality.

BACKGROUND: Lipid-lowering therapy plays an important role in preventing the recurrence of cardiovascular events in patients after acute myocardial infarction (AMI). This study aimed to assess the effect of intensified low density lipoprotein cholesterol (LDL-C) reduction on recurrent myocardial infarction and cardiovascular mortality in patients after AMI. METHOD: The 562 enrolled AMI patients (84.2% male) were divided into two groups according to 3-month LDL-C decrease percentage equal to or more than 40% (n = 165) and less than 40% (n = 397). To evaluate the long-term efficacy of LDL-C reduction, the 5-year outcomes were collected, including time to the first occurrence of myocardial infarction and time to cardiovascular death. RESULTS: The baseline characteristics and complication rates were not different between the two study groups. The patients with 3-month LDL-C decrease ≥ 40% had higher baseline LDL-C and lower 3-month, 1-year, 2-year, 3-year, 4-year and 5-year LDL-C than the patients with 3-month LDL-C decrease < 40%. In Kaplan-Meier analyses, those patients with 3-month LDL-C decrease ≥ 40% had a higher rate of freedom from myocardial infarction (p = 0.006) and survival rate (p = 0.02) at 5-year follow-up. The 3-month LDL-C < 40% parameter was significantly related to cardiovascular death (HR: 9.62, 95% CI 1.18-78.62, p < 0.04). CONCLUSIONS: After acute myocardial infarction, 3-month LDL-C decrease < 40% was identified to be a significant risk factor for predicting 5-year cardiovascular death. The patients with 3-month LDL-C decrease ≥ 40% had a higher rate of freedom from myocardial infarction and lower cardiovascular mortality, even though these patients had higher baseline LDL-C value. KEY WORDS: Acute myocardial infarction; Cardiovascular death; Low-density lipoprotein cholesterol; Mortality; Statin.

Body Mass Index and Outcome of Acute Myocardial Infarction - Is There an Obesity Paradox?

BACKGROUND: Although there have been some studies focusing on the relationship between body mass index (BMI), coronary artery disease (CAD) and acute coronary syndrome, the clinical effects of BMI on outcomes after percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI) are not well known in a Taiwanese population. METHODS: From January 2005 to December 2011, 1298 AMI patients who received PCI were enrolled from a single center in Taiwan. The patients were divided into 4 groups according to their BMI: underweight (BMI < 18.5 kg/m(2)); normal weight (18.5 ≤ BMI < 24 kg/m(2)); overweight (24 ≤ BMI < 27 kg/m(2)) and obese (BMI ≥ 27). All patients had been followed up for at least 12 months, and 30-day and 5-year all-cause and cardiovascular-cause mortality were compared among the study groups. RESULTS: The patients in the underweight group had a lower 30-day survival rate than the other 3 groups, and the underweight and normal weight patients had a lower 5-year survival rate than the overweight and obese patients. The multivariate regression analysis showed that Killip class ≥ 2, non-use of statin, older age, hemoglobin < 12 g/dl and chronic kidney disease, but not BMI, are independent predictors of all-cause mortality. CONCLUSIONS: In this present study, the major factors affecting long-term survival are lack of using statin and older age, but not obese paradox. KEY WORDS: Acute myocardial infarction; Mortality; Obesity; Percutaneous coronary intervention; Survival.

An open-label randomized noninferior study of generic name and brand name of propafenone for rhythm control in patients with paroxysmal atrial fibrillation.

BACKGROUND: Propafenone is a class IC antiarrhythmic agent that is commonly used as the first-line therapy for patients with paroxysmal atrial fibrillation (AF) in Taiwan. This study compared the efficacy and safety of generic (Rhynorm) and brand name (Rytmonorm) propafenone for rhythm control of paroxysmal AF in Taiwan. METHODS: This was an open-label randomized multicenter noninferior study conducted in Taiwan. We enrolled 76 patients with AF. To investigate the efficacy of propafenone, we used a wearable electrocardiogram (ECG) event recorder to evaluate the daily burden of AF episodes in patients for 24 weeks. The primary efficacy endpoint was the frequency of AF with clinical significance, which was indicated by AF duration ≥30 seconds. The safety endpoints included proarrhythmic or hemodynamic adverse events. RESULT: To analyze the efficacy and safety of these agents, 71 patients (five patients with screen failure) were randomized to two groups, specifically a Rhynorm group (n = 37) and a Rytmonorm group (n = 34), for 24 weeks of the treatment period. The baseline patient characteristics were comparable between the groups. However, the Rhynorm group was older (65.4 ± 8.40 vs 59.8 ± 10.8 years; p = 0.02). The primary efficacy endpoint at week 24 decreased by 4.76% ± 18.5% (from 24.3% ± 33.9% to 19.0% ± 28.7%; p = 0.13) in the Rhynorm group and by 3.27% ± 15.2% (from 16.9% ± 26.4% to 13.6% ± 19.2%; p = 0.22) in the Rytmonorm group, with an intergroup difference of 1.5% ± 17.0%; p = 0.71. This finding indicates that Rhynorm is not inferior to Rytmonorm ( p = 0.023 for noninferiority). The safety profile of the agents was comparable between the two groups. CONCLUSION: Our results verified that Rhynorm was noninferior to Rytmonorm in terms of efficacy and safety for treating paroxysmal AF in Taiwan ( ClinicalTrials.gov Identifier: NCT03674658).

Neural mechanism of atrial fibrillation: insight from global high density frequency mapping.

BACKGROUND: It has been demonstrated that intrinsic cardiac autonomic activation of ganglionated plexi (GPs) exhibits a frequency gradient from the center to the periphery with limited mapping. OBJECTIVE: We aimed to use a global mapping tool (Ensite Array) to identify the frequency distribution and clarify the interaction between the extrinsic/intrinsic autonomic systems. METHODS: A mid sternal thoractomy was performed in anesthetized dogs. High frequency stimulation (20 Hz, 0.1 ms duration) was applied to locate the GPs and achieve vagosympathetic stimulation (VNS). There were 4 major GPs, which were located near the 4 pulmonary vein (PV) ostia, and a third fat pad (SVC-Ao) GP that was located near the superior vena cava (SVC)-right atrial (RA) junction. RESULTS: Without VNS (n = 12), the left atrial (LA) mean (8.20 ± 0.11 vs 7.95 ± 0.30 Hz, P = 0.04) and max (9.86 ± 0.28 vs 9.43 ± 0.29 Hz, P = 0.03) DFs were higher during the PV ostial GP stimulation than the SVC-Ao GP stimulation. The LA max DFs were located not only at the primary GPs but also the nearby secondary PV ostial GPs. The RA mean DF (8.36 ± 0.05 vs 7.99 ± 0.19 Hz, P = 0.04) was higher during SVC-Ao GP stimulation than PV ostial GP stimulation. The max DF was located inside the SVC during SVC-Ao GP stimulation and at the RA septum during PV ostial GP stimulation. With VNS (n = 12), the LA mean and max DFs between the PV ostial and SVC-Ao GP stimulation were similar. The DF distribution shifted to non-GP LA sites during both the PV ostial and SVC-Ao GP stimulation. CONCLUSION: The findings indicate that the AF was caused by an interaction between the PV ostial GPs during intrinsic autonomic stimulation, whereas the non-GP LA sites were responsible for the AF induced by an extrinsic neural input.

Recurrent syncope due to carotid sinus hypersensitivity and sick sinus syndrome.

Syncope is a sudden and brief loss of consciousness with postural tone. Its recovery is usually spontaneous. There are various causes of syncope including cardiac, vascular, neurologic, metabolic and miscellaneous origins. The tracing is usually time-consuming and costly. The diagnosis of carotid sinus syncope may sometimes be difficult since the symptoms are nonspecific, especially in older persons. Here, we report the case of a 72-year-old woman who sought medical attention at our hospital due to repeated syncope episodes over the previous 5 years. Neurologic examinations showed negative results (including brain computed tomography). Twenty-four-hour ambulatory electrocardiogram monitoring showed atrial and ventricular premature contractions only. Electrophysiologic study disclosed prolonged corrected sinus node recovery time (1,737 ms) with poor atrioventricular conduction. Drop of blood pressure together with sinus bradycardia developed after left side carotid sinus massage. Both carotid sinus hypersensitivity with sick sinus syndrome contributed to this patient's syncope, and after pacemaker placement together with selective serotonin reuptake inhibitor treatment, she was free from syncope thereafter.

Tissue Doppler velocity is not totally preload-independent: a study in a uremic population after hemodialysis.

OBJECTIVES: The aim of this study was to investigate the changes of regional tissue Doppler velocity after volume removal following regular hemodialysis (HD) in uremic patients. Is tissue Doppler velocity really preload-independent? BACKGROUND: Diastolic dysfunction was divided into four stages: normal pattern, abnormal relaxation pattern, pseudonormalization pattern, and restrictive pattern. Pulse wave Doppler and color Doppler echocardiography were important diagnostic tools for these forms of diastolic dysfunction. However, they were preload-dependent and sometimes there was confusion between the normal pattern and the pseudonormalization pattern. Tissue Doppler echocardiography was promising for problems in diastolic dysfunction and appeared to be preload-independent. However, there are still some disputes over this point. METHODS: Ninety-three uremic patients receiving regular HD were included in the study. There were 45 males and 48 females aged 59 +/- 14 years. The mean volume removed after HD was 2.3 +/- 0.9 kg. The mean heart rates before and after HD were 77 +/- 11 and 76 +/- 12 beats per minute, respectively (p = 0.73). All patients received complete transthoracic echocardiography examinations before and after HD. The studies included cardiac chamber size, left ventricular systolic performance, pulse wave Doppler echocardiographic data of mitral inflow and the right upper pulmonary vein including peak velocity of early diastolic E wave, E wave time velocity integral (TVI-E), peak velocity of late diastolic A wave, A wave TVI, systolic phase of pulmonary vein (S wave TVI), early diastolic phase of pulmonary vein (D wave TVI) and atrial contraction phase of pulmonary vein (Ar wave TVI). Pulsed tissue Doppler echocardiography (TDE) was performed and a 4-mm sample volume was placed at the 6 corners of the mitral annulus including septal, lateral, anterior, inferior, anteroseptal and posterior corners. Five to ten cardiac cycles were recorded and the data were averaged. Measurements performed included peak velocity of systolic phase (Sa), early diastolic phase (Ea), late diastolic phase (Aa), Ea/Aa ratio and time from the beginning of electrocardiogram Q wave to the beginning of Sa (Q-Sa time). The same measurements were repeated after HD. RESULTS: After HD, left atrium diameter and left ventricular internal dimensions at end diastole became smaller. There were significant reductions for mitral peak E wave velocity, TVI-E, peak A wave velocity and E/A ratio. As for the pulmonary vein, systolic phase of pulmonary vein and early diastolic phase of pulmonary vein decreased significantly. Peak Ar wave did not change significantly. For TDE, Sa and Aa did not change but Ea did decrease. CONCLUSION: After HD, there is a significant reduction of intravascular effective volume. No significant change is found for myocardial peak systolic velocity and peak late diastolic velocity. However, there is a significant reduction of myocardial early diastolic phase peak velocity. This suggests that TDE is not completely preload-independent; at least, it is phase-dependent within each cardiac cycle.

An observational study on the effect of premature ventricular complex burden on long-term outcome.

The long-term clinical impact of premature ventricular complexes (PVCs) on mortality and morbidity has not been fully studied. This study aimed to investigate the association between the burden of PVCs and adverse clinical outcome.A total of 5778 subjects, who were pacemaker-free and ventricular tachycardia-free at baseline, received 24-hour electrocardiography monitoring between January 1, 2002 and December 31, 2004. Clinical event data were retrieved from the Bureau of National Health Insurance of Taiwan. Multivariate Cox hazards regression models and propensity-score matching were applied to assess the association between PVCs and adverse clinical outcome.Average follow-up time was 10[REPLACEMENT CHARACTER]±â€Š1 year. In all, 1403 subjects expired, 1301 subjects were hospitalized in the cardiovascular (CV) ward, 3384 were hospitalized for any reason, and 631 subjects developed new-onset heart failure (HF). The optimal cut-off PVC frequency (12 beats per day) was obtained through receiver operator characteristic curves, with a sensitivity of 58.4% and specificity of 59.8%. Upon multivariate analysis, a PVC frequency >12 beats per day was an independent predictor for all mortality (hazard ratio [HR]: 1.429, 95% confidence interval [CI]: 1.284-1.590), CV hospitalization (HR: 1.127, 95% CI: 1.008-1.260), all-cause hospitalization (HR 1.094, 95% CI: 1.021-1.173), and new-onset HF (HR: 1.411, 95% CI: 1.203-1.655). Subjects with a PVC frequency >12 beats per day had an increased risk of cardiac death attributable to HF and sudden cardiac death. The incidence rates for mortality and HF were significantly increased in cases of raised PVC frequency. Propensity-score matching analysis also echoed the main findings.Increased PVC burden was associated with a higher incidence of all-cause mortality, CV hospitalization, all-cause hospitalization, and new-onset HF which was independent of other clinical risk factors.

Role of shortened QTc dispersion in in-hospital cardiac events in patients undergoing percutaneous coronary intervention for acute coronary syndrome.

BACKGROUND: QT dispersion (QTD) refers to the difference between maximal and minimal QT values on the electrocardiogram (ECG). QTD values are calculated and corrected with Bazett's formula (corrected QTD = QTcD = QTD/square root of RR). QTcD increases in patients with acute coronary syndrome (ACS). Recovery of increased QTcD (shortened QTcD) develops after successful revascularization, but prolonged QTcD occurs in certain patients. The aim of this study is to ascertain the clinical significance between shortened and prolonged QTcD groups after percutaneous coronary intervention (PCI). METHODS: We retrospectively enrolled 128 patients with ACS who had received PCI. The values of QTcD were measured manually on 12-lead standard ECGs obtained within 3 days before and after PCI (pre-PCI QTcD and post-PCI QTcD). All the patients were divided into 2 groups. The shortened QTcD group was defined as those patients with a decrease in QTcD after PCI and the prolonged QTcD group as those with an increase in QTcD after PCI. The underlying diseases, various clinical classifications and some prognostic factors were taken into comparison and statistical analysis between these 2 groups. RESULTS: The shortened QTcD group showed a significantly higher rate of in-hospital cardiac death (13% vs. 0%, p = 0.006) and a greater pre-PCI QTcD (100.8 +/- 39.5 vs. 61.3 +/- 24.1 ms, p < 0.001) than the prolonged QTcD group. There was a significantly greater pre-PCI QTcD in patients with cardiac death than those without cardiac death (111.6 +/- 38.3 vs. 83.3 +/- 38.3ms, p = 0.027). Furthermore, the patients with in-hospital cardiac death presented with a significantly more frequent occurrence of in-hospital ventricular arrhythmia, compared with those without cardiac death (30.0% vs. 4.0%, p = 0.014). CONCLUSION: Among the patients with ACS undergoing PCI, directly divided into shortened and prolonged QTcD groups regardless of initial pre-PCI QTcD, the shortened QTcD group showed a higher occurrence of in-hospital cardiac death and a greater pre-PCI QTcD. Shortened QTcD might be 1 risk factor for in-hospital cardiac death.

Periesophageal vagal plexus injury is a favorable outcome predictor after catheter ablation of atrial fibrillation.

BACKGROUND: Collateral damage to periesophageal vagal plexus associated with symptomatic gastric hypomotility and associated symptoms are not uncommon after catheter ablation of atrial fibrillation (AF). The injury may indicate transmural ablation lesions. OBJECTIVE: The purpose of this study was to evaluate the periesophageal vagal plexus injury (PNI) and long-term outcome after catheter ablation of AF. METHODS: A total of 441 consecutive patients with AF (mean age 54.71 ± 10.52 years; 134 women) who underwent catheter ablation (paroxysmal AF, n = 312; persistent AF, n = 129) were retrospectively enrolled from 2011 to 2013; group 1 was defined as patients with PNI and associated symptoms (n = 88), and group 2 was defined as patients without PNI or associated symptoms (n = 353). Baseline characteristics and electrophysiological properties were collected to analyze the relationship between PNI and clinical outcome. The association of AF recurrence after catheter ablation and PNI symptoms was also investigated. RESULTS: During a mean follow-up period of 37.3 ± 0.94 months, group 1 had longer AF-freedom days in sinus rhythm after AF ablation and had less recurrence after the blanking period compared with group 2 (mean recurrence days, 1254.22 ± 45.26 days vs 1065.21 ± 33.35 days; P < .01). Multivariate analysis also revealed that PNI was an independently protective predictor of AF recurrence (hazard ratio 0.527; 95% confidence interval 0.289-0.959; P = .036). There was no difference in baseline characteristics, CHA2DS2-VASc score, or echocardiography follow-up duration. CONCLUSION: PNI and associated symptoms are not uncommon after catheter ablation of AF. A better long-term outcome is thereby independently predicted, suggesting transmural ablation lesions during pulmonary vein isolation.