Sex-based differences in left ventricular assist device clinical outcomes.

BACKGROUND: Heart failure (HF) continues to be a significant public health issue, posing a heightened risk of morbidity and mortality for both genders. Despite the widespread use of left ventricular assist device (LVAD), the influence of gender differences on clinical outcomes following implantation remains unclear. OBJECTIVES: We investigated the impact of gender differences on readmission rates and other outcomes following LVAD implantation in patients admitted with advanced HF. METHODS: We conducted a retrospective study of patients who underwent LVAD implantation for advanced HF between 2014 and 2020, using the Nationwide Readmissions Database. Our study cohort was divided into male and female patients. The primary outcome was 30-day readmission (30-dr), while secondary outcomes were inpatient mortality, length of stay (LOS), procedural complication rates, and periadmission rates. Multivariate linear, Cox, and logistic regression analyses were performed. RESULTS: During the study period, 11,492 patients with advanced HF who had LVAD placement were identified. Of these, 22% (n = 2532) were females and 78% (n = 8960) were males. The mean age was 53.9 ± 10.8 years for females and 56.3 ± 10.5 years for males (adjusted Wald test, p < 0.01). Readmissions were higher in females (21% vs. 17%, p = 0.02) when compared to males. Cox regression analysis showed higher readmission events (hazard ratio: 1.24, 95% confidence interval: 1.01-1.52, p = 0.03) in females when compared to males. Inpatient mortality, LOS, and most procedural complication rates were not statistically significantly different between the two groups (p > 0.05, all). CONCLUSION: Women experienced higher readmission rates and were more likely to be readmitted multiple times after LVAD implantation when compared to their male counterparts. However, there were no significant sex-based differences in inpatient mortality, LOS, and nearly all procedural complication rates. These findings suggest that female patients may require closer monitoring and targeted interventions to reduce readmission rates.

Geographic variability and operator trends of transcatheter edge-to-edge repair in the United States.

BACKGROUNDS: Transcatheter edge-to-edge repair (TEER) devices are used for primary mitral regurgitation (MR) and secondary MR. Despite the growing use of TEER devices, there have not been many studies on operator experience or procedure volumes by state. AIMS: We aimed to investigate nationwide operator volume trends and geographic variation in access to TEER. METHODS: The United States Center for Medicare and Medicaid Services (CMS) National Medicare Provider Utilization and Payment Database (MPUPD) was analyzed between 2015 and 2020 for initial TEER procedures. RESULTS: Procedure volume and total operators increased yearly from 2015 to 2019 but declined in 2020. Mean annual procedure volume per operator varied significantly by state, between 0 in multiple states and 35 in North Dakota. In 2019, 994 unique operators were identified, with 295 operators documented performing 10 or more procedures (29.68%). Operators performing 10 or more TEER procedures provided 68.46% of all operations in 2019, averaging 20.94 procedures per operator. CONCLUSIONS: TEER procedures are becoming increasingly common as more operators are being trained. However, significant variability exists in the procedural volume per operator.

A Remote Nutritional Intervention to Change the Dietary Habits of Patients Undergoing Ablation of Atrial Fibrillation: Randomized Controlled Trial.

BACKGROUND: The Prevention With Mediterranean Diet (PREDIMED) trial supported the effectiveness of a nutritional intervention conducted by a dietitian to prevent cardiovascular disease. However, the effect of a remote intervention to follow the Mediterranean diet has been less explored. OBJECTIVE: This study aims to assess the effectiveness of a remotely provided Mediterranean diet-based nutritional intervention in obtaining favorable dietary changes in the context of a secondary prevention trial of atrial fibrillation (AF). METHODS: The PREvention of recurrent arrhythmias with Mediterranean diet (PREDIMAR) study is a 2-year multicenter, randomized, controlled, single-blinded trial to assess the effect of the Mediterranean diet enriched with extra virgin olive oil (EVOO) on the prevention of atrial tachyarrhythmia recurrence after catheter ablation. Participants in sinus rhythm after ablation were randomly assigned to an intervention group (Mediterranean diet enriched with EVOO) or a control group (usual clinical care). The remote nutritional intervention included phone contacts (1 per 3 months) and web-based interventions with provision of dietary recommendations, and participants had access to a web page, a mobile app, and printed resources. The information is divided into 6 areas: Recommended foods, Menus, News and Online resources, Practical tips, Mediterranean diet classroom, and Your personal experience. At baseline and at 1-year and 2-year follow-up, the 14-item Mediterranean Diet Adherence Screener (MEDAS) questionnaire and a semiquantitative food frequency questionnaire were collected by a dietitian by phone. RESULTS: A total of 720 subjects were randomized (365 to the intervention group, 355 to the control group). Up to September 2020, 560 subjects completed the first year (560/574, retention rate 95.6%) and 304 completed the second year (304/322, retention rate 94.4%) of the intervention. After 24 months of follow-up, increased adherence to the Mediterranean diet was observed in both groups, but the improvement was significantly higher in the intervention group than in the control group (net between-group difference: 1.8 points in the MEDAS questionnaire (95% CI 1.4-2.2; P<.001). Compared with the control group, the Mediterranean diet intervention group showed a significant increase in the consumption of fruits (P<.001), olive oil (P<.001), whole grain cereals (P=.002), pulses (P<.001), nuts (P<.001), white fish (P<.001), fatty fish (P<.001), and white meat (P=.007), and a significant reduction in refined cereals (P<.001), red and processed meat (P<.001), and sweets (P<.001) at 2 years of intervention. In terms of nutrients, the intervention group significantly increased their intake of omega-3 (P<.001) and fiber (P<.001), and they decreased their intake of carbohydrates (P=.02) and saturated fatty acids (P<.001) compared with the control group. CONCLUSIONS: The remote nutritional intervention using a website and phone calls seems to be effective in increasing adherence to the Mediterranean diet pattern among AF patients treated with catheter ablation. TRIAL REGISTRATION: ClinicalTrials.gov NCT03053843; https://www.clinicaltrials.gov/ct2/show/NCT03053843.

A constant postpacing interval in response to overdrive pacing with variable number of beats: An aid in the identification of entrainment for a particular pacing train during macroreentrant atrial tachycardias.

BACKGROUND: When pacing trains with a constant cycle length (CL) but increasing number of beats are introduced during a macroreentrant atrial tachycardia (MAT), the postpacing interval (PPI) is expected to increase if entrainment does not occur but could be stable if entrainment occurs. We tested the ability of PPI analysis to detect entrainment. METHODS: Synchronized pacing trains with increasing number of beats (1-20) were delivered from the coronary sinus (CS) and lateral right atrium (RA) at a CL 20 ms shorter than the MAT CL. Pacing trains were grouped in pairs differing by one-paced beat, and the ∆PPI measured. RESULTS: In an initial prospective cohort of 21 patients (48% had left atrial flutter) the mean ∆PPI was 21.3 ± 5.6 ms for pairs of pacing trains in which neither entrained the MAT and 2.8 ± 1.4 ms for those in which both entrained the MAT (P < .0001). Results were similar for common vs atypical flutter, PPI-TCL ≤30 ms vs PPI-TCL >30 ms, presence vs absence of antiarrhythmic drugs and faster vs slower MAT. When an index pacing train was compared to one with two-paced beats less, a PPI difference of <19 ms identified entrainment with 95% sensitivity and 98% specificity. In a validation cohort of 16 patients, this cut-off value resulted in sensitivity and specificity of 90% and 94%. CONCLUSIONS: A relatively constant ∆PPI in response to overdrive pacing with identical CL but different number of beats allows accurate discrimination between trains that entrained vs those which did not entrain a MAT.

A scoring algorithm for the accurate differential diagnosis of regular wide QRS complex tachycardia.

BACKGROUND: The differential diagnosis of regular wide QRS complex tachycardia (RWQRST) remains the subject of numerous publications, all of which aim at diagnosis during the acute phase. Although an accurate diagnosis is necessary to make long-term decisions, it often leads to invasive testing. METHODS: Criteria with high positive predictive values (PPVs) for diagnosis can be obtained by analyzing the electrocardiogram (ECG) data during RWQRST and comparing them with these data at baseline. By assigning points to these criteria, a scoring algorithm to accurately diagnose numerous patients can be obtained. A total of 352 consecutive patients with RWQRST were included. Two electrophysiologists blind to patient condition analyzed the 16 criteria considered as having high PPVs. RESULTS: A total of 149 (42.3%) cases were supraventricular tachycardia (SVT), and 203 (57.7%) cases were ventricular tachycardia (VT). A higher percentage of patients with VT had structural heart disease (86.7% vs 16.1%). Seven of the 16 criteria analyzed had PPVs > 95%, and each criterion was assigned a score. A final score of -1 was indicative of SVT (PPV 98%); a score of 1 was indicative of VT (PPV 98%); and a score of ≥2 was indicative of VT (PPV 100%). A score of ≠0 was obtained for 51.7% of all cases of tachycardia, making it possible to reach a highly accurate diagnosis in approximately half of all cases. No cases of VT scored -1, and no cases of SVT scored ≥2. CONCLUSIONS: The current scoring system stands out for its high PPV (98%) and specificity (98%), enabling an accurate diagnosis for more than half of the patients.

Comparative Effects of Sodium Bicarbonate and Intravenous Lipid Emulsions on Reversing Bupivacaine-Induced Electrophysiological Toxicity in a Porcine Experimental Model.

BACKGROUND: Bupivacaine cardiotoxicity mainly manifests as inhibition of the cardiac sodium channel, which slows conduction, particularly at the ventricular level. Experimental studies have demonstrated that intravenous lipid emulsions (ILEs) can reduce the cardiotoxic effects of bupivacaine, but the extent of these effects is controversial. Sodium bicarbonate (B) represents the standard treatment of toxicity related to sodium channel-blocking drugs. The aim of this study was to compare the effects of ILEs and B on the speed of recovery from bupivacaine-induced effects on the electrocardiographic parameters. METHODS: Bupivacaine 4 mg/kg was administered to 24 anesthetized pigs. Three minutes after delivering the bupivacaine bolus, the animals were given the following: ILE 1.5 mL/kg followed by 0.25 mL/kg/min (ILE group) and B 2 mEq/kg followed by 1 mEq/kg/h (B group). Controls (C group) were given saline solution, 50 mL followed by 1 mL/kg/h. Electrophysiological parameters were evaluated in sinus rhythm and during right ventricular pacing at several time intervals up to 30 minutes. Data were analyzed as the area under the curve (AUC) for the first 10 minutes (AUC10) or 30 minutes (AUC30). RESULTS: Bupivacaine increased the sinus cycle length, PR interval, and QRS duration. AUC30 of the sinus rhythm QRS duration after antidote administration was significantly different among the 3 groups (P = .003). B group experienced faster recovery from intoxication than the C group (AUC10, P = .003; AUC30, P = .003) or the ILE group (AUC10, P = .018). During the first minute, 50% of the B group (versus 0% of the ILE and C groups) had recovered >30% of QRS duration (P = .011). The trend toward faster recovery in the ILE group than in the C group did not reach significance (AUC10, P = .23; AUC30, P = .06). Effects on the paced QRS duration at a rate of 150 bpm were more intense but with similar results (B versus C group: AUC10, P = .009; AUC30, P = .009; B versus ILE: AUC10, P = .015; AUC30, P = .024). The recovery process of the paced QRS tended to be slower for all antidotes. CONCLUSIONS: In a closed-chest swine model, B was an effective treatment for electrophysiological alterations caused by established bupivacaine toxicity. At clinical doses, B ameliorated bupivacaine electrocardiographic toxicity faster than ILE. Use-dependent effects of bupivacaine are prominent and delay the effects of both antidotes, but B produces faster recovery than ILE.

Differential effects of sevoflurane and propofol on swine cardiac conduction system.

OBJECTIVE: To compare the effects of sevoflurane and propofol on the porcine cardiac conduction system. STUDY DESIGN: A prospective, comparative study of electrophysiological properties of anaesthetics agents in an experimental porcine model. ANIMALS: A total of 36 hybrid Landrace-Large White pigs. METHODS: After premedication with 20 mg kg-1 of intramuscular ketamine, anaesthesia was induced with 4.5 mg kg-1propofol intravenously. In 18 consecutive animals, anaesthesia was maintained with propofol (13 mg kg-1 hour-1) and in the remaining 18 animals with 2.66% sevoflurane. The femoral artery and vein were canalized for invasive monitoring, analytical blood gas sampling and intracardiac catheter insertion. Following instrumentation and after a period of stabilization, a customary electrophysiological evaluation was performed. We compared the electrophysiology of the sinus and atrioventricular node (AV) node under sevoflurane or propofol anaesthesia, and the effects of both anaesthetics on atrial and ventricular refractoriness. RESULTS: There was a significant difference in sinus node recovery time between sevoflurane and propofol (907 ± 231 versus 753 ± 146 ms, p = 0.02). Sevoflurane in comparison with propofol significantly prolonged specialized AV conduction times, represented by an increased Wenckebach cycle length (272 ± 54 versus 235 ± 40 ms, p = 0.03) and AV nodal refractoriness (327 ± 34 versus 287 ± 30 ms, p = 0.002). In addition, sevoflurane prolonged ventricular refractoriness (298 ± 27 versus 255 ± 38 ms, p = 0.007) and the QT corrected interval (0.50 ± 0.05 versus 0.46 ± 0.09 ms, p = 0.005). CONCLUSIONS AND CLINICAL RELEVANCE: Sevoflurane in comparison with propofol, depresses several parameters of sinus and AV nodal function and prolongs the ventricular refractoriness of the porcine cardiac conduction system. These findings should be taken into consideration for the choice of anaesthetic agents in clinical and experimental settings.

Safety and efficacy of cryoablation vs. radiofrequency ablation of septal accessory pathways: systematic review of the literature and meta-analyses.

Aims: Radiofrequency ablation (RFA) of septal accessory pathways (APs) is associated with a significant rate of first procedure failures and complications. Cryoablation is an alternative energy source but there are no studies comparing both ablation techniques. We aimed to systematically review the literature and compare the efficacy and safety of cryoablation vs. RFA of septal APs. Methods and results: We conducted two separate meta-analysis of cryoablation and RFA of septal APs and calculated the global estimates of the efficacy and safety. Sixty-four articles were included: 38 articles reporting RFA and 27 articles reporting cryoablation procedures. Additionally, we included the previously non-published cryoablation registry of septal APs performed at our institution. Overall, 4244 septal APs constitute our study population, 3495 in the RFA cohort and 749 in the cryoablation cohort. Acute procedural success rate of cryoablation was 86.0% (95% CI 81.6-89.4%) and RFA 89.0% (95% CI 86.8-91.0%). Recurrence rate of cryoablation was 18.1% (95% CI 14.8-21.8%) and RFA 9.9% (95% CI 8.2-12.0%). Long-term success rate after multiple ablation procedures of cryoablation was 75.9% (95% CI 68.2-82.3%) and RFA 88.4% (95% CI 84.7-91.3%). There were no reported cases of persistent atrioventricular block (AVB) with cryoablation and 2.7% (95% CI 2.2-3.4%) with RFA. Conclusion: Studies of RFA for treatment of septal APs report higher efficacy rates than do studies using cryoablation, but a significantly higher rate of AVB.

Randomized comparison of intravenous procainamide vs. intravenous amiodarone for the acute treatment of tolerated wide QRS tachycardia: the PROCAMIO study.

AIMS: Intravenous procainamide and amiodarone are drugs of choice for well-tolerated ventricular tachycardia. However, the choice between them, even according to Guidelines, is unclear. We performed a multicentre randomized open-labelled study to determine the safety and efficacy of intravenous procainamide and amiodarone for the acute treatment of tolerated wide QRS complex (probably ventricular) tachycardia. METHODS AND RESULTS: Patients were randomly assigned to receive intravenous procainamide (10 mg/kg/20 min) or amiodarone (5 mg/kg/20 min). The primary endpoint was the incidence of major predefined cardiac adverse events within 40 min after infusion initiation. Of 74 patients included, 62 could be analysed. The primary endpoint occurred in 3 of 33 (9%) procainamide and 12 of 29 (41%) amiodarone patients (odd ratio, OR = 0.1; 95% confidence interval, CI 0.03-0.6; P = 0.006). Tachycardia terminated within 40 min in 22 (67%) procainamide and 11 (38%) amiodarone patients (OR = 3.3; 95% CI 1.2-9.3; P = 0.026). In the following 24 h, adverse events occurred in 18% procainamide and 31% amiodarone patients (OR: 0.49; 95% CI: 0.15-1.61; P: 0.24). Among 49 patients with structural heart disease, the primary endpoint was less common in procainamide patients (3 [11%] vs. 10 [43%]; OR: 0.17; 95% CI: 0.04-0.73, P = 0.017). CONCLUSIONS: This study compares for the first time in a randomized design intravenous procainamide and amiodarone for the treatment of the acute episode of sustained monomorphic well-tolerated (probably) ventricular tachycardia. Procainamide therapy was associated with less major cardiac adverse events and a higher proportion of tachycardia termination within 40 min.

Prospective European survey on atrial fibrillation ablation: clinical characteristics of patients and ablation strategies used in different countries.

BACKGROUND: Atrial fibrillation (AF) ablation is widely adopted. Our aim was to conduct a prospective multicenter survey to verify patients' characteristics, approaches, and technologies adopted across Europe. METHODS AND RESULTS: A total of 35 centers in 12 countries actively participated in the study and 940 patients (median age 60 years) were enrolled. AF was paroxysmal, persistent, and long-lasting persistent in 52.4%, 36%, and 11.6% of patients, respectively; 95.5% of patients were symptomatic and 91.4% were refractory to antiarrhythmic therapy. Redo procedures were performed in 20.9%. Pulmonary vein isolation (PVI) emerged as the cornerstone of ablative therapy and has been performed in 98.7% of procedures, with confirmation of PVI in 92.9% of cases. The ablation of nonparoxysmal AF was not generally limited to isolating the PVs and several adjunctive approaches are adopted, particularly in the case of long-lasting persistent AF. Linear lesions or elimination of complex fractionated atrial electrograms were more frequently added. Circular mapping catheters and imaging techniques were seen to be used in about two-thirds of cases. Radiofrequency energy was delivered through open irrigated catheters in 68% of cases. CONCLUSIONS: European centers are largely following the recommendations of the guidelines and the expert consensus documents for AF ablation. AF ablation is mainly performed in relatively young patients with symptomatic drug refractory AF and no or minimal heart disease. Patients with paroxysmal AF are the most frequently treated with a quite uniform ablative approach across Europe. A less standardized approach was observed in nonparoxysmal AF patients.

Current Trends in Hypertension Identification and Management: Insights from the National Health and Nutrition Examination Survey (NHANES) Following the 2017 ACC/AHA High Blood Pressure Guidelines.

BACKGROUND: Hypertension is a global health issue associated with increased cardiovascular morbidity and mortality. This study aimed to investigate contemporary hypertension identification and management trends following the 2017 American College of Cardiology/American Heart Association guidelines. METHODS AND RESULTS: Data from the National Health and Nutrition Examination Survey conducted from 2017 to 2020 were analyzed. Participants between 20 and 79 years of age were included. Participants were stratified into different treatment groups based on indication and guideline adherence. Descriptive statistics were used to compare medication use, diagnosis rates, and blood pressure control. A total of 265 402 026 people met the inclusion criteria, of which 19.0% (n=50 349 209) were undergoing guideline antihypertensive management. In the guideline antihypertensive management group, a single antihypertensive class was used to treat 45.7% of participants, and 55.2% had uncontrolled blood pressure. Participants not undergoing guideline antihypertensive management qualified for primary prevention in 11.5% (n=24 741 999) of cases and for secondary prevention in 2.4% (n=5 070 044) of cases; of these, 66.3% (n=19 774 007) did not know they may have hypertension and were not on antihypertensive medication. CONCLUSIONS: Adherence to guidelines for antihypertensive management is suboptimal. Over half of patients undergoing guideline treatment had uncontrolled blood pressure. One-third of qualifying participants may not be receiving treatment. Education and medical management were missing for 2 in 3 qualifying participants. Addressing these deficiencies is crucial for improving blood pressure control and reducing cardiovascular event outcomes.

Negative effects of COVID-19 on the implantation rate of cardiac resynchronization therapy with defibrillator device.

Introduction: COVID-19 drastically impacted the landscape of the United States' medical system. Limited data is available on the nationwide implantation trends in Cardiac Resynchronization Therapy Defibrillator (CRT-D) devices before and during the pandemic. We aimed to explore the impact of the COVID-19 pandemic on CRT-D insertion rates and adverse outcomes related to delays in care. Methods and Results: We conducted a retrospective cross-sectional analysis using the National Inpatient Sample database between 2017 and 2020. Variables were identified using their ICD-10 codes. Inclusion criteria: age ≥ 18 years, presenting for a nonelective admission, primary diagnosis of hypertensive heart disease, hypertensive heart, chronic kidney disease, or heart failure, and underwent insertion of a CRT-D. Between 2017 and 2020, CRT-D devices were inserted during 23,635 admissions. On average, 6198 devices were implanted yearly from 2017 to 2019, with only 5040 devices being implanted in 2020. Additionally, reduced implantation rates were noted for every cohort of hospital size, location, and teaching status during this year. The year 2020 also had the highest average death rate at 1.39%, but this difference was statistically insignificant (adjusted Wald test p = .767), and COVID-19 was not associated with an increased risk of inpatient mortality (OR 0.22, 95% CI 0.03-1.82, p = .162). Conclusion: The COVID-19 pandemic has affected all facets of the healthcare system, especially surgical volume rates. CRT-D procedures significantly decreased in 2020. This is the first retrospective study highlighting the trend of reduced rates of CRT-D implantation as a response to the COVID-19 pandemic.

Mediterranean diet and epicardial adipose tissue in patients with atrial fibrillation treated with ablation: a substudy of the 'PREDIMAR' trial.

AIMS: To analyse the relationship between Mediterranean diet (MedDiet) adherence and epicardial adipose tissue (EAT) in patients with atrial fibrillation (AF) and the association between EAT or MedDiet adherence at baseline with AF recurrence after ablation. METHODS AND RESULTS: We included 199 patients from the PREDIMAR trial (PREvención con DIeta Mediterránea de Arritmias Recurrentes), in a single centre in this substudy. All of them had a computed tomography with EAT measurement. Lifestyle and clinical characteristics were obtained at baseline. The traditional MedDiet pattern was defined according to the MedDiet Adherence Screener (MEDAS). Any documented AF > 30 s after ablation was considered a recurrence. Multivariable-adjusted linear and logistic regression models were run to assess the cross-sectional association of MedDiet with EAT, and of EAT with the AF type at baseline. Also, Cox regression models were used to prospectively assess the associations of MedDiet adherence and EAT with AF recurrences after ablation. Median EAT was 135 g (interquartile range: 112-177), and the mean MedDiet score was 7.75 ± 2 points. A higher MEDAS ≥ 7 that was associated with lower odds of an EAT ≥ 135 g [multivariable odds ratio (mOR) = 0.45; 95% CI = 0.22-0.91; P = 0.025] was significantly associated with persistent AF after adjusting for traditional risk factors (mOR: 2.22; 95% CI: 1.03-4.79; P = 0.042). No significant associations were observed between EAT ≥ 135 g and the risk of atrial tachyarrhythmia recurrences after ablation [multivariable-adjusted hazard ratio (mHR) = 1.18; 95% CI: 0.72-1.94; P = 0.512], or between MEDAS ≥ 7 and AF recurrence (mHR = 0.78; 95% CI: 0.47-1.31; P = 0.344). CONCLUSION: In patients with AF, higher adherence to MedDiet is associated with a significantly lower amount of EAT. Epicardial adipose tissue ≥ 135 g was significantly associated with persistent AF.

Mediterranean diet consumption is significantly associated with a lower amount of epicardial adipose tissue in patients with atrial fibrillation treated with ablation. A higher amount of epicardial adipose tissue is significantly associated with a persistent pattern of atrial fibrillation that is well known as a more aggressive and difficult to treat type of atrial fibrillation. The risk of arrhythmic recurrence after ablation tended to be associated with a larger amount of epicardial adipose tissue. Adherence to Mediterranean diet is associated with a non-significantly lower risk of arrhythmic recurrences after ablation.

Differentiation of atrioventricular nodal reentrant tachycardia from orthodromic reciprocating tachycardia by the resetting response to ventricular extrastimuli: comparison to response to continuous ventricular pacing.

BACKGROUND: The usefulness of ventricular entrainment to differentiate AV nodal reentrant tachycardia (AVNRT) from orthodromic reciprocating tachycardia (ORT) by substracting the corrected postpacing interval (cPPI) from the tachycardia cycle length (TCL) or the ventriculoatrial interval during stimulation (SA) from that during tachycardia (VA) have been widely validated. However, some tachycardias are interrupted by pacing trains but may not be so by ventricular extrastimuli resulting in resetting. OBJECTIVES: To validate prospectively the diagnostic yield of cPPI-TCL and SA-VA measurements after resetting and to determine the proportion of AVNRT and ORT that can be entrained and/or reset from the right ventricular apex (RVA). METHODS: 223 consecutive patients with inducible AVNRT or ORT underwent pacing trains and single extrastimulus (also double extrastimuli if singles did not reset tachycardia) at the RVA. We calculated cPPI-TCL and SA-VA during entrainment and resetting. RESULTS: Entrainment could not be achieved in 15.2% of tachycardias because of consistent tachycardia interruption by pacing; resetting was observed in 99.5%. Values of cPPI-TCL and SA-VA > 110 milliseconds after resetting identified AVNRT as accurately as after entrainment. Values for cPPI-TCL/ SA-VA were: sensitivity: 98/100%; specificity: 96/98%; positive predictive value: 98/99%; negative predictive value: 98/100%. CONCLUSIONS: Determinations of cPPI-TCL and SA-VA after resetting with single or double RVA extrastimuli are useful maneuvers to differentiate AVNRT from ORT and can be used for nearly every inducible AVNRT or ORT, even if they are interrupted by ventricular trains.

Resetting and entrainment of reentrant arrhythmias: part II: informative content and practical use of these responses.

This paper is the second part of a review of the phenomena of resetting and entrainment of reentrant arrhythmias. It describes the practical and clinical uses of resetting and entrainment, including the results of a variety of studies for these purposes. Given the amount of information generated, it is out of the scope of this review to comment in detail about each of the published studies. We rather present the basis for each described clinical use and for each type of arrhythmia in which these phenomena have been used with illustrative examples. The review covers: resetting response patterns; resetting/entrainment and termination; resetting/entrainment, fusion, and reentry; analysis of the postpacing interval; concealed entrainment; resetting/entrainment as an aid in the differential diagnosis among different arrhythmic mechanisms; usefulness of these phenomena in arrhythmic mechanisms other than macrorreentry. Finally, we make some comments about the recent use of these phenomena and propose two new criteria for entrainment recognition.

Resetting and entrainment of reentrant arrhythmias: part I: concepts, recognition, and protocol for evaluation: surface ECG versus intracardiac recordings.

In this paper, we review the information accumulated over the years regarding the phenomena of resetting and entrainment of reentrant arrhythmias. Over three decades of research and clinical applications, these phenomena have demonstrated that they stay as a main tool for an intellectual understanding of reentry and to base strategies for localization of critical areas for ablative therapies. This review will be divided into two parts. This first part deals with the bases for the concept development, the means for the detection of these phenomena, and their mechanistic implications. Resetting is described as a particular response of a given rhythm to an external perturbation, indicating interaction between them. Entrainment indicates continuous reset of the rhythm when the perturbation is repetitive. The mechanisms that explain these responses in reentrant rhythms are presented. Fusion, both at the surface electrocardiogram and at the level of intracardiac recordings, is discussed in detail, with its value and limitations as a key concept to recognize entrainment and reentry. Computer simulations are used as an aid to a better understanding. Differences between resetting and entrainment are considered, and a pacing protocol to study these phenomena described.

Acute Right Coronary artery Occlusion During Cooled-Tip Radiofrequency Ablation of the Cavotricuspid Isthmus.

Cooled-tip radiofrequencycatheter ablation of the cavotricuspid isthmus, performed after pulmonary vein isolation, resulted in acute occlusion of the posterolateral branch of the right coronary artery in a 49-year-old male with previously known right coronary artery disease. The occlusion was successfully stented. It is conceivable that previously diseased coronary arteries are more prone to be damaged during ablation.

Assessment of cardiotoxicity and plasma ropivacaine concentrations after serratus intercostal fascial plane block in an experimental model.

Serratus intercostal fascial plane block (SIFPB) has emerged as an alternative to paravertebral block in breast surgery. It involves the administration of high volumes and doses of local anesthetics (LA) that can potentially reach toxic levels. Ropivacaine is widely used in thoraco-fascial blocks; however, there is no information on the plasma concentrations attained after SIPFB and whether they are associated with cardiotoxicity. Plasma concentrations of ropivacaine and its electrophysiological effects were evaluated in eight pigs after bilateral SIFPB with ropivacaine in doses of 3 mg/kg. Plasma concentrations, electrophysiological and hemodynamic parameters were measured sequentially for the following 180 min until the end of the study. The area under the curve, the maximum plasma concentration (Cmax) and the time to reach Cmax (tmax) were calculated. The median arterial ropivacaine concentration Cmax was, 2.34 [1.40 to 3.74] µg/ml. The time to reach the highest concentration was 15 [10 to 20] min. Twenty-five percent of the animals had arterial concentrations above the lower limit concentration of ropivacaine for LA systemic toxicity (3.4 µg/ml). No alterations were observed in the electrophysiological or electrocardiographic parameters except for a prolongation of the QTc interval, from 489 ± 30 to 544 ± 44 ms (Δ11.38 ± 6%), P = 0.01. Hemodynamic parameters remained in the physiological range throughout the study. SIFPB with ropivacaine in doses of 3 mg/kg has reached potentially toxic levels, however, it has not been associated with adverse electrophysiological or hemodynamic effects.

Sodium bicarbonate reverts electrophysiologic cardiotoxicity of ropivacaine faster than lipid emulsions in a porcine model.

Ropivacaine has been described as a safer local anaesthetic (LA); however, serious cardiotoxic accidents have been reported. Intravenous-lipid-emulsion (ILE) therapy during LA intoxication seems to act as an antidote. Sodium bicarbonate is the standard treatment for sodium channel blocker drug toxicity. We compared both antidotes on the reversion of electrophysiologic toxicity induced by ropivacaine. Ropivacaine 5 mg kg-1 was administered in 24 pigs, and 3 min later, the animals received ILE: 1.5 ml kg-1  + 0.25 ml kg-1  min-1 (ILE group); sodium bicarbonate: 2 mEq kg-1  + 1 mEq kg-1  h-1 (NaHCO3 group); saline solution (CTL group). Electrophysiological parameters were evaluated for 30 min. The area under the curve (AUC) for the first 5 or 30 min was compared between groups. Ropivacaine induced a lengthening of the PR interval by 17% (P = 0.0001), His-ventricle-interval by 58% (P = 0.001), sinus QRS complex by 56% (P = 0.0001), paced QRS at 150 bpm by 257% (P = 0.0001), and at 120 bpm by 143% (P = 0.0001) in all groups. At 5 min after treatment, sinus QRS in the NaHCO3 group was shorter than that in the CTL group (AUCQRS5 , P = 0.003) or ILE group (AUCQRS5 , P = 0.045). During the first minute, seven of the animals in the NaHCO3 group vs. two in the ILE or 0 in the CTL group recovered more than 30% of the sinus QRS previously lengthened by ropivacaine (P = 0.003). Sodium bicarbonate reversed the electrophysiological toxicity of ropivacaine faster than ILE and control groups.