Personalized pulmonary vein isolation with very high-power short-duration lesions guided by left atrial wall thickness: the QDOT-by-LAWT randomized trial.

AIMS: Pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (PAF) using very high-power short-duration (vHPSD) radiofrequency (RF) ablation proved to be safe and effective. However, vHPSD applications result in shallower lesions that might not be always transmural. Multidetector computed tomography-derived left atrial wall thickness (LAWT) maps could enable a thickness-guided switching from vHPSD to the standard-power ablation mode. The aim of this randomized trial was to compare the safety, the efficacy, and the efficiency of a LAWT-guided vHPSD PVI approach with those of the CLOSE protocol for PAF ablation (NCT04298177). METHODS AND RESULTS: Consecutive patients referred for first-time PAF ablation were randomized on a 1:1 basis. In the QDOT-by-LAWT arm, for LAWT ≤2.5 mm, vHPSD ablation was performed; for points with LAWT > 2.5 mm, standard-power RF ablation titrating ablation index (AI) according to the local LAWT was performed. In the CLOSE arm, LAWT information was not available to the operator; ablation was performed according to the CLOSE study settings: AI ≥400 at the posterior wall and ≥550 at the anterior wall. A total of 162 patients were included. In the QDOT-by-LAWT group, a significant reduction in procedure time (40 vs. 70 min; P < 0.001) and RF time (6.6 vs. 25.7 min; P < 0.001) was observed. No difference was observed between the groups regarding complication rate (P = 0.99) and first-pass isolation (P = 0.99). At 12-month follow-up, no significant differences occurred in atrial arrhythmia-free survival between groups (P = 0.88). CONCLUSION: LAWT-guided PVI combining vHPSD and standard-power ablation is not inferior to the CLOSE protocol in terms of 1-year atrial arrhythmia-free survival and demonstrated a reduction in procedural and RF times.

Scar architecture affects the electrophysiological characteristics of induced ventricular arrhythmias in hypertrophic cardiomyopathy.

AIMS: Late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) detects myocardial scarring, a risk factor for ventricular arrhythmias (VAs) in hypertrophic cardiomyopathy (HCM). The LGE-CMR distinguishes core, borderzone (BZ) fibrosis, and BZ channels, crucial components of re-entry circuits. We studied how scar architecture affects inducibility and electrophysiological traits of VA in HCM. METHODS AND RESULTS: We correlated scar composition with programmed ventricular stimulation-inducible VA features using LGE intensity maps. Thirty consecutive patients were enrolled. Thirteen (43%) were non-inducible, 6 (20%) had inducible non-sustained, and 11 (37%) had inducible sustained mono (MMVT)- or polymorphic VT/VF (PVT/VF). Of 17 induced VA, 13 (76%) were MMVT that either ended spontaneously, persisted as sustained monomorphic, or degenerated into PVT/VF. Twenty-seven patients (90%) had LGE. Of these, 17 (57%) had non-sustained or sustained inducible VA. Scar mass significantly increased (P = 0.002) from non-inducible to inducible non-sustained and sustained VA patients in both the BZ and core components. Borderzone channels were found in 23%, 67%, and 91% of non-inducible, inducible non-sustained, and inducible sustained VA patients (P = 0.003). All 13 patients induced with MMVT or monomorphic-initiated PVT/VF had LGE. The origin of 10/13 of these VTs matched scar location, with 8/10 of these LGE regions showing BZ channels. During follow-up (20 months, interquartile range: 7-37), one patient with BZ channels and inducible PVT had an ICD shock for VF. CONCLUSION: Scar architecture determines inducibility and electrophysiological traits of VA in HCM. Larger studies should explore the role of complex LGE patterns in refining risk assessment in HCM patients.

Assessing left atrial intramyocardial fat infiltration from computerized tomography angiography in patients with atrial fibrillation.

AIMS: Epicardial adipose tissue might promote atrial fibrillation (AF) in several ways, including infiltrating the underlying atrial myocardium. However, the role of this potential mechanism has been poorly investigated. The aim of this study is to evaluate the presence of left atrial (LA) infiltrated adipose tissue (inFAT) by analysing multi-detector computer tomography (MDCT)-derived three-dimensional (3D) fat infiltration maps and to compare the extent of LA inFAT between patients without AF history, with paroxysmal, and with persistent AF. METHODS AND RESULTS: Sixty consecutive patients with AF diagnosis (30 persistent and 30 paroxysmal) were enrolled and compared with 20 age-matched control; MDCT-derived images were post-processed to obtain 3D LA inFAT maps for all patients. Volume (mL) and mean signal intensities [(Hounsfield Units (HU)] of inFAT (HU -194; -5), dense inFAT (HU -194; -50), and fat-myocardial admixture (HU -50; -5) were automatically computed by the software. inFAT volume was significantly different across the three groups (P = 0.009), with post-hoc pairwise comparisons showing a significant increase in inFAT volume in persistent AF compared to controls (P = 0.006). Dense inFAT retained a significant difference also after correcting for body mass index (P = 0.028). In addition, more negative inFAT radiodensity values were found in AF patients. Regional distribution analysis showed a significantly higher regional distribution of LA inFAT at left and right superior pulmonary vein antra in AF patients. CONCLUSION: Persistent forms of AF are associated with greater degree of LA intramyocardial adipose infiltration, independently of body mass index. Compared to controls, AF patients present higher LA inFAT volume at left and right superior pulmonary vein antra.

Clinical impact of aging on outcomes of cardioneuroablation for reflex syncope or functional bradycardia: Results from the cardionEuroabLation: patiEnt selection, imaGe integrAtioN and outComEs-The ELEGANCE multicenter study.

BACKGROUND: Cardioneuroablation (CNA) is a novel treatment for reflex syncope. The effect of aging on CNA efficacy is not fully understood. OBJECTIVE: The purpose of this study was to assess the impact of aging on candidacy and efficacy of CNA for treating vasovagal syncope (VVS), carotid sinus syndrome (CSS), and functional bradyarrhythmia. METHODS: The ELEGANCE (cardionEuroabLation: patiEnt selection, imaGe integrAtioN and outComEs) multicenter study assessed CNA in patients with reflex syncope or severe functional bradyarrhythmia. Patients underwent pre-CNA Holter electrocardiography (ECG), head-up tilt testing (HUT), and electrophysiological study. CNA candidacy and efficacy was assessed in 14 young (18-40 years), 26 middle-aged (41-60 years), and 20 older (>60 years) patients. RESULTS: Sixty patients (37 men; mean age 51 ± 16 years) underwent CNA. The majority (80%) had VVS, 8% had CSS, and 12% had functional bradycardia/atrioventricular block. Pre-CNA Holter ECG, HUT, and electrophysiological findings did not differ across age groups. Acute CNA success was 93%, without differences between age groups (P = .42). Post-CNA HUT response was negative in 53%, vasodepressor in 38%, cardioinhibitory in 7%, and mixed in 2%, without differences across age groups (P = .59). At follow-up (8 months, interquartile range 4-15), 53 patients (88%) were free of symptoms. Kaplan-Meier curves did not show differences in event-free survival between age groups (P = .29). The negative predictive value of a negative HUT was 91.7%. CONCLUSION: CNA is a viable treatment for reflex syncope and functional bradyarrhythmia in all ages, and is highly effective in mixed VVS. HUT is a key step in postablation clinical assessment.

Personalized pulmonary vein antrum isolation guided by left atrial wall thickness for persistent atrial fibrillation.

AIMS: Pulmonary vein (PV) antrum isolation proved to be effective for treating persistent atrial fibrillation (PeAF). We sought to investigate the results of a personalized approach aimed at adapting the ablation index (AI) to the local left atrial wall thickness (LAWT) in a cohort of consecutive patients with PeAF. METHODS AND RESULTS: Consecutive patients referred for PeAF first ablation were prospectively enrolled. The LAWT three-dimensional maps were obtained from pre-procedure multidetector computed tomography and integrated into the navigation system. Ablation index was titrated according to the local LAWT, and the ablation line was personalized to avoid the thickest regions while encircling the PV antrum. A total of 121 patients (69.4% male, age 64.5 ± 9.5 years) were included. Procedure time was 57 min (IQR 50-67), fluoroscopy time was 43 s (IQR 20-71), and radiofrequency (RF) time was 16.5 min (IQR 14.3-18.4). The median AI tailored to the local LAWT was 387 (IQR 360-410) for the anterior wall and 335 (IQR 300-375) for the posterior wall. First-pass PV antrum isolation was obtained in 103 (85%) of the right PVs and 103 (85%) of the left PVs. Median LAWT values were higher for PVs without first-pass isolation as compared to the whole cohort (P = 0.02 for left PVs and P = 0.03 for right PVs). Recurrence-free survival was 79% at 12 month follow-up. CONCLUSION: In this prospective study, LAWT-guided PV antrum isolation for PeAF was effective and efficient, requiring low procedure, fluoroscopy, and RF time. A randomized trial comparing the LAWT-guided ablation with the standard of practice is in progress (ClinicalTrials.gov, NCT05396534).

Outcomes of cavotricuspid isthmus-dependent flutter ablation: randomized study comparing single vs. multiple catheter procedures-the SIMPLE study.

BACKGROUND: Catheter ablation is recommended as first-line therapy for patients with symptomatic typical AFl. Although the conventional multi-catheter approach is the standard of care for cavotricuspid isthmus (CTI) ablation, a single-catheter approach was recently described as a feasible alternative. The present study sought to compare safety, efficacy, and efficiency of single vs. multi-catheter approach for atrial flutter (AFl) ablation. METHODS: In this randomized multi-center study, consecutive patients referred for AFl ablation (n = 253) were enrolled and randomized to multiple vs. single-catheter approach for CTI ablation. In the single-catheter arm, PR interval (PRI) on the surface ECG was used to prove CTI block. Procedural and follow-up data were collected and compared between the two arms. RESULTS: 128 and 125 patients were assigned to the single-catheter and to the multi-catheter arms, respectively. In the single-catheter arm, procedure time was significantly shorter (37 ± 25 vs. 48 ± 27 minutes, p = 0.002) and required less fluoroscopy time (430 ± 461 vs. 712 ± 628 seconds, p < 0.001) and less radiofrequency time (428 ± 316 vs. 643 ± 519 seconds, p < 0.001), achieving a higher first-pass CTI block rate (55 (45%) vs. 37 (31%), p = 0.044), compared with the multi-catheter arm. After a median follow-up of 12 months, 11 (4%) patients experienced AFl recurrences (5 (4%) in the single-catheter arm and 6 (5%) in the multi-catheter arm, p = 0.99). No differences were found in arrhythmia-free survival between arms (log-rank = 0.71). CONCLUSIONS: The single-catheter approach for typical AFl ablation is not inferior to the conventional multiple-catheter approach, reducing procedure, fluoroscopy, and radiofrequency time.

Relationship of the T-wave Tpeak-Tend interval with conduction system disorders in arterial hypertension / Relación del intervalo Tpico-Tfinal de la onda T con trastornos del sistema de conducción en hipertensión arterial

Abstract Purpose: The Tpeak-Tend interval of the T wave has emerged as a new electrocardiographic marker of increased transmural dispersion of ventricular repolarization. We aimed to determine the presence of cardiac conduction system disorders in patients with systemic arterial hypertension (SAH) who have altered Tpeak-Tend interval of the T wave. Methods: The 67 patients with SAH were divided into two groups. Those with prolonged (≥ 77 ms) Tpeak-Tend intervals, 21 (31%) patients were in the study group. Those with normal (< 77 ms) Tpeak-Tend intervals, 46 (69%) patients were in the control group. Alteration of ventricular repolarization manifested as a prolongation of the Tpeak-Tend interval was detected by computerized electrocardiographic analysis tools. Results: The median value of QRS complex duration was significantly wider in the study group as compared to the control group (110 ± 12 ms vs. 94 ± 8 ms p < 0.001). There was a significantly greater incidence of left anterior hemiblock in the study group (14% vs. 0% p < 0.04). The median value of the QTc interval was significantly greater in the study group (440 ± 26 vs. 422 ± 15 p < 0.01). There was a significantly greater incidence of patients with prolonged QTc interval in the study group (33% vs. 11% p < 0.02). The median value of the Tpeak-Tend interval was significantly greater in the study group (84 ± 5 ms vs. 65 ± 4 ms p < 0.001), as well as, the Tpeak-Tend/QTc ratio in the study group (0.19 ± 0.1 vs. 0.16 ± 0.1 p < 0.001). Conclusion: There is a significantly greater ventricular repolarization disorders and abnormalities of the cardiac conduction system in SAH patients who possess altered Tpeak-Tend interval of the T wave.

Resumen Objetivo: El intervalo Tpico-Tfinal de la onda T es un marcador electrocardiográfico de la dispersión transmural aumentada de la repolarización ventricular. Investigamos la presencia de trastornos del sistema de conducción cardíaca en pacientes con hipertensión arterial sistémica (HA) que poseen alterado el intervalo Tpico-Tfinal de la onda T. Métodos: Los 67 pacientes con HA fueron divididos en dos grupos. Aquellos con intervalos de Tpico-Tfinal prolongados (≥ 77 ms), 21 (31%) pacientes (grupo de estudio). Aquellos con intervalos normales (< 77 ms) Tpico-Tfinal, 46 (69%) pacientes (grupo control). Los intervalos Tpico-Tfinal fueron medidos por herramientas de análisis electrocardiográfico computarizado. Resultados: El valor mediano de la duración del complejo QRS fue significativamente más amplio en el grupo de estudio (110 ± 12 ms vs. 94 ± 8 ms p < 0.001). Hubo una incidencia significativamente mayor de hemibloqueo anterior izquierdo en el grupo de estudio (14% vs. 0% p < 0.04). El valor mediano del intervalo QTc fue significativamente mayor en el grupo de estudio (440 ± 26 vs. 422 ± 15 p < 0.01). Hubo una incidencia significativamente mayor de pacientes con intervalo QTc prolongado en el grupo de estudio (33% vs. 11% p < 0.02). El valor mediano del intervalo Tpico-Tfinal fue significativamente mayor en el grupo de estudio (84 ± 5 ms vs. 65 ± 4 ms p < 0.001), así como el cociente Tpico-Tfinal/QTc (0.19 ± 0.1 vs. 0.16 ± 0.1 p < 0.001). Conclusión: Existe una alteración de la repolarización ventricular significativamente mayor y anomalías del sistema de conducción cardíaca en pacientes con HA que poseen alteración del intervalo Tpico-Tfinal de la onda T.

A hybrid clinical and electrocardiographic score to predict the origin of outflow tract ventricular arrhythmias.

BACKGROUND: To predict the outflow tract ventricular arrhythmias (OTVA) site of origin (SOO) before the ablation procedure has important practical implications. The present study sought to prospectively evaluate the accuracy of a clinical and electrocardiographic hybrid algorithm (HA) for the prediction of OTVAs-SOO, and at the same time to develop and to prospectively validate a new score with improved discriminatory capacity. METHODS: In this multicenter study, we prospectively enrolled consecutive patients referred for OTVA ablation (N = 202), and we divided them in a derivation sample and a validation cohort. Surface ECGs during OTVA were analyzed to compare previous published ECG-only criteria and to develop a new score. RESULTS: In the derivation sample (N = 105), the correct prediction rate of HA and ECG-only criteria ranged from 74 to 89%. R-wave amplitude in V3 was the best ECG parameter for discriminating LVOT origin in V3 precordial transition (V3PT) patients, and was incorporated to the novel weighted hybrid score (WHS). WHS correctly classified 99 (94.2%) patients, presenting 90% sensitivity and 96% specificity (AUC 0.97) in the entire population; WHS mantained a 87% sensitivity and 91% specificity (AUC 0.95) in patients with V3PT subgroup. The high discriminatory capacity was confirmed in the validation sample (N = 97): the WHS exhibited an AUC (0.93), and a WHS ≥ 2 allowed a correct prediction of LVOT origin in 87 (90.0%) cases, yielding a sensitivity of 87% and specificity of 90%; moreover, the V3PT subgroup showed an AUC of 0.92, and a punctuation ≥ 2 predicted an LVOT origin with a sensitivity of 94% and specificity of 78%. CONCLUSIONS: The novel hybrid score has proved to accurately anticipate the OTVA's origin, even in those with a V3 precordial transition. A Weighted hybrid score. B Typical examples of the use of the weighted hybrid score. C ROC analysis of WHS and previous ECG criteria for prediction of LVOT origin in the derivation cohort. D ROC analysis of WHS and previous ECG criteria for prediction of LVOT origin in the V3 precordial transition OTVA subgroup.

Relationship of the T-wave Tpeak-Tend interval with conduction system disorders in arterial hypertension.

PURPOSE: The Tpeak-Tend interval of the T wave has emerged as a new electrocardiographic marker of increased transmural dispersion of ventricular repolarization. We aimed to determine the presence of cardiac conduction system disorders in patients with systemic arterial hypertension (SAH) who have altered Tpeak-Tend interval of the T wave. METHODS: The 67 patients with SAH were divided into two groups. Those with prolonged (≥ 77 ms) Tpeak-Tend intervals, 21 (31%) patients were in the study group. Those with normal (< 77 ms) Tpeak-Tend intervals, 46 (69%) patients were in the control group. Alteration of ventricular repolarization manifested as a prolongation of the Tpeak-Tend interval was detected by computerized electrocardiographic analysis tools. RESULTS: The median value of QRS complex duration was significantly wider in the study group as compared to the control group (110 ± 12 ms vs. 94 ± 8 ms p < 0.001). There was a significantly greater incidence of left anterior hemiblock in the study group (14% vs. 0% p < 0.04). The median value of the QTc interval was significantly greater in the study group (440 ± 26 vs. 422 ± 15 p < 0.01). There was a significantly greater incidence of patients with prolonged QTc interval in the study group (33% vs. 11% p < 0.02). The median value of the Tpeak-Tend interval was significantly greater in the study group (84 ± 5 ms vs. 65 ± 4 ms p < 0.001), as well as, the Tpeak-Tend/QTc ratio in the study group (0.19 ± 0.1 vs. 0.16 ± 0.1 p < 0.001). CONCLUSION: There is a significantly greater ventricular repolarization disorders and abnormalities of the cardiac conduction system in SAH patients who possess altered Tpeak-Tend interval of the T wave.

OBJETIVO: El intervalo Tpico-Tfinal de la onda T es un marcador electrocardiográfico de la dispersión transmural aumentada de la repolarización ventricular. Investigamos la presencia de trastornos del sistema de conducción cardíaca en pacientes con hipertensión arterial sistémica (HA) que poseen alterado el intervalo Tpico-Tfinal de la onda T. MÉTODOS: Los 67 pacientes con HA fueron divididos en dos grupos. Aquellos con intervalos de Tpico-Tfinal prolongados (≥ 77 ms), 21 (31%) pacientes (grupo de estudio). Aquellos con intervalos normales (< 77 ms) Tpico-Tfinal, 46 (69%) pacientes (grupo control). Los intervalos Tpico-Tfinal fueron medidos por herramientas de análisis electrocardiográfico computarizado. RESULTADOS: El valor mediano de la duración del complejo QRS fue significativamente más amplio en el grupo de estudio (110 ± 12 ms vs. 94 ± 8 ms p < 0.001). Hubo una incidencia significativamente mayor de hemibloqueo anterior izquierdo en el grupo de estudio (14% vs. 0% p < 0.04). El valor mediano del intervalo QTc fue significativamente mayor en el grupo de estudio (440 ± 26 vs. 422 ± 15 p < 0.01). Hubo una incidencia significativamente mayor de pacientes con intervalo QTc prolongado en el grupo de estudio (33% vs. 11% p < 0.02). El valor mediano del intervalo Tpico-Tfinal fue significativamente mayor en el grupo de estudio (84 ± 5 ms vs. 65 ± 4 ms p < 0.001), así como el cociente Tpico-Tfinal/QTc (0.19 ± 0.1 vs. 0.16 ± 0.1 p < 0.001). CONCLUSIÓN: Existe una alteración de la repolarización ventricular significativamente mayor y anomalías del sistema de conducción cardíaca en pacientes con HA que poseen alteración del intervalo Tpico-Tfinal de la onda T.

Preventive substrate ablation in chronic post-myocardial infarction patients with high-risk scar characteristics for ventricular arrhythmias: rationale and design of PREVENT-VT study.

BACKGROUND: Recent studies showed that an early strategy for ventricular tachycardia (VT) ablation resulted in reduction of VT episodes or mortality. Cardiac magnetic resonance (CMR)-derived border zone channel (BZC) mass has proved to be a strong non-invasive predictor of VT in post-myocardial infarction (MI). CMR-guided VT substrate ablation proved to be safe and effective for reducing sudden cardiac death (SCD) and VA occurrence. METHODS: PREVENT-VT is a prospective, randomized, multicenter, and controlled trial designed to evaluate the safety and efficacy of prophylactic CMR-guided VT substrate ablation in chronic post-MI patients with CMR-derived arrhythmogenic scar characteristics. Chronic post-MI patients with late gadolinium enhancement (LGE) CMR will be evaluated. CMR images will be post-processed and the BZC mass measured: patients with a BZC mass > 5.15 g will be eligible. Consecutive patients will be enrolled at 3 centers and randomized on a 1:1 basis to undergo a VT substrate ablation (ABLATE arm) or optimal medical treatment (OMT arm). Primary prevention ICD will be implanted following guideline recommendations, while non-ICD candidates will be implanted with an implantable cardiac monitor (ICM). The primary endpoint is a composite outcome of sudden cardiac death (SCD) or sustained monomorphic VT, either treated by an ICD or documented with ICM. Secondary endpoints are procedural safety and efficiency outcomes of CMR-guided ablation. DISCUSSION: In some patients, the first VA episode causes SCD or severe neurological damage. The aim of the PREVENT-VT is to evaluate whether primary preventive substrate ablation may be a safe and effective prophylactic therapy for reducing SCD and VA occurrence in patients with previous MI and high-risk scar characteristics based on CMR. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04675073, registered on January 1, 2021.

Relationship between the posterior atrial wall and the esophagus: esophageal position and temperature measurement during atrial fibrillation ablation (AWESOME-AF). A randomized controlled trial.

BACKGROUND: Pulmonary vein isolation (PVI) implies unavoidable ablation lesions to the left atrial posterior wall, which is closely related to the esophagus, leading to several potential complications. This study evaluates the usefulness of the esophageal fingerprint in avoiding temperature rises during paroxysmal atrial fibrillation (PAF) ablation. METHODS: Isodistance maps of the atrio-esophageal relationship (esophageal fingerprint) were derived from the preprocedural computerized tomography. Patients were randomized (1:1) into two groups: (1) PRINT group, the PVI line was modified according to the esophageal fingerprint; (2) CONTROL group, standard PVI with operator blinded to the fingerprint. The primary endpoint was temperature rise detected by intraluminal esophageal temperature probe monitoring. Ablation settings were as specified on the Ablate BY-LAW study protocol. RESULTS: Sixty consecutive patients referred for paroxysmal AF ablation were randomized (42 (70%) men, mean age 60 ± 11 years). Temperature rise (> 39.1 °C) occurred in 5 (16%) patients in the PRINT group vs. 17 (56%) in the CONTROL group (p < 0.01). Three AF recurrences were documented at a mean follow-up of 12 ± 3 months (one (3%) in the PRINT group and 2 (6.6%) in the CONTROL group, p = 0.4). CONCLUSION: The esophageal fingerprint allows for a reliable identification of the esophageal position and its use for PVI line deployment results in less frequent esophageal temperature rises when compared to the standard approach. Further studies are needed to evaluate the impact of PVI line modification to avoid esophageal heating on long-term outcomes. The development of new imaging-derived tools could ultimately improve patient safety (NCT04394923).

Disfunción del nódulo sinusal asociado a estenosis severa proximal de la arteria coronaria derecha y vasoespasmo coronario

RESUMEN La disfunción del nódulo sinusal (DNS) es generalmente secundaria a la senescencia del nodo sinusal y del miocardio auricular circundante. Estamos presentando un paciente de 59 años de edad, hipertenso sin tratamiento y con antecedente de síncope en dos oportunidades en los últimos 4 meses. Ingresa debido a un flutter auricular con conducción auriculoventricular 1:1 con una frecuencia cardiaca de 280 lat/min que cede con goteo de amiodarona. Un Holter de 24 horas demostró un ritmo sinusal predominante, episodios paroxísticos de fibrilación auricular con respuesta ventricular alta, bradicardia sinusal de 47 lat/min. Se realizó el diagnóstico de disfunción del nódulo sinusal, Rubenstein tipo III (Síndrome Bradicardia-Taquicardia). Una coronariografía constató una estenosis del 80% en segmento proximal de la arteria coronaria derecha con componente espástico. La arteria del nódulo sinusal emerge del segmento proximal de la coronaria derecha. Se realizó una angioplastia exitosa con stent medicado. Otro estudio Holter de 24 horas de control pos-angioplastia registró nuevamente episodios paroxísticos de fibrilación auricular con respuesta ventricular alta y episodios de pausas de hasta 3.100 milisegundos por lo que se implantó un marcapasos bicameral. A pesar del restablecimiento de un flujo sanguíneo adecuado a la arteria del nódulo sinusal con la angioplastia de la coronaria derecha no se obtuvo una mejoría de la disfunción del nódulo sinusal.

ABSTRACT Sinus node dysfunction (SND) is generally secondary to senescence of the sinus node and the surrounding atrial myocardium. We are presenting a 59-year-old patient, hypertensive without treatment and with a history of syncope on two occasions in the last 4 months. He was admitted due to a 1: 1 atrioventricular conduction atrial flutter with a heart rate of 280 beats/min that subsides with an amiodarone drip. A 24-hour Holter monitor showed predominant sinus rhythm, paroxysmal episodes of atrial fibrillation with high ventricular response, sinus bradycardia of 47 beats/min. The diagnosis of sinus node dysfunction, Rubenstein type III (Bradycardia-Tachycardia Syndrome) was made. A coronary angiography confirmed an 80% stenosis in the proximal segment of the right coronary artery with a spastic component. The sinus node artery emerges from the proximal segment of the right coronary artery. A successful angioplasty was performed with a medicated stent. Another 24-hour Holter study of post-angioplasty control again recorded paroxysmal atrial fibrillation with high ventricular response episodes and pause episodes of up to 3,100 milliseconds, for which a dual-chamber pacemaker was implanted. Despite the restoration of adequate blood flow to the sinus node artery with right coronary angioplasty, no improvement in sinus node dysfunction was obtained.

Rol de la morfología y dispersión de la onda P en la predicción de fibrilación auricular

RESUMEN Las características anisotrópicas ocasionadas por un miocardio auricular patológico pueden jugar un papel importante en la creación de circuitos de reentrada al causar propagación no homogénea y discontinua del impulso en el miocardio auricular. Este miocardio auricular alterado puede generar bloqueo unidireccional, retraso de la conducción y ritmos auriculares reentrantes. En estas condiciones la onda P del electrocardiograma (ECG) puede mostrar alteraciones que pueden asociarse con arritmias auriculares y fibrilación auricular (FA). La dispersión de la onda P (DP) se considera un marcador no invasivo del ECG para el remodelado auricular y es predictor sensible y específico del desarrollo de FA. Se ha demostrado que el aumento de la duración de la onda P y la DP reflejan la prolongación del tiempo de conducción auricular dentro de la aurícula derecha y entre ambas aurículas, y una propagación auricular no homogénea y discontinua de los impulsos sinusales. Un valor de corte de 40 ms de la DP demostró tener una sensibilidad del 83%, una especificidad del 85% y un valor predictivo positivo del 89% para la identificación de pacientes con antecedentes de FA paroxística aislada. Los pacientes con alteración de la morfología de la onda P y dispersión de la onda P en el ECG tienen una gran susceptibilidad a desarrollar FA porque poseen electrogramas endocárdicos auriculares anormalmente prolongados y fraccionados, una duración de onda P significativamente mayor, un tiempo de conducción intraauricular e interauricular significativamente más largo, y una mayor incidencia de inducción de fibrilación auricular sostenida.

ABSTRACT The anisotropic characteristics caused by a pathological atrial myocardium can play an important role in the creation of reentry circuits by causing discontinuous and inhomogeneous impulse propagation in the atrial myocardium. This altered atrial myocardium can lead to unidirectional block, conduction delay, and reentrant atrial rhythms. Under these conditions, the P wave of the electrocardiogram (ECG) can demonstrate alterations that can be associated with atrial arrhythmias and atrial fibrillation (AF). The P-wave dispersion (PD) is considered a non-invasive ECG marker for atrial remodeling and is a sensitive and specific predictor of the development of AF. Increased P wave duration and PD have been shown to reflect prolonged atrial conduction time within the right atrium and between both atria, and discontinuous, inhomogeneous atrial propagation of sinus impulses. A cutoff value of 40 ms for PD was shown to have a sensitivity of 83%, a specificity of 85%, and a positive predictive value of 89% for the identification of patients with a history of isolated paroxysmal AF. Patients with abnormal P wave morphology and P wave dispersion on the ECG are highly susceptible to developing AF because they have abnormally prolonged and fractionated atrial endocardial electrograms, significantly longer P wave duration, and significantly longer intra-atrial and inter-atrial conduction time, and a higher incidence of sustained atrial fibrillation induction.

The relation between QRS complex fragmentation and segmental abnormalities of the myocardial contractility in patients with coronary artery disease.

BACKGROUND: Fragmented QRS (fQRS) is defined as any QRS complex with duration of less than 120 ms (ms) and at least one notch in the R or S wave in two or more leads belonging to the same coronary territory. The fQRS represents a delay in ventricular conduction caused by a myocardial scar associated to arrhythmic events. METHODS: This is a descriptive, retrospective, cross-sectional study of a total of 123 patientsadmitted with ischemic heart disease. The aim was to correlate the presence of fQRS in a conventional 12-leads electrocardiogram (ECG) with myocardial regional motility disorders. RESULTS: A total of 62% of the patients were male, the mean age was 63 ± 12 SD. fQRS was observed in 44% (64% men and 36% women), the most frequent location being the inferior wall (61%), followed by the anteroseptal and lateral walls (14% for both). Of the 36 patients with fQRS, 30 had segmental disorders, while 6 did not. Of the 45 patients without fQRS, 28 had segmental disorders, but 17 did not, which gives us a sensitivity of 52% (moderate SnNout) and specificity of 74% (high SpPin), with a positive predictive value of 83%, a negative predictive value of 38% and a prevalence of 72%. CONCLUSION: The presence of fQRS in the ECG has high specificity and a high positive predictive value of the existence of segmental myocardial motility disorders in patients with documented coronary artery disease.

Myocardial Fibrosis as a Pathway of Prediction of Ventricular Arrhythmias and Sudden Cardiac Death in Patients With Nonischemic Dilated Cardiomyopathy.

The mechanism of sudden cardiac death (SCD) in patients with nonischemic dilated cardiomyopathy (NIDCM) is mostly due to sustained ventricular tachycardia and ventricular fibrillation. The clinical guidelines for the therapeutic management of this set of patients are mostly based on left ventricular ejection fraction value which has a low specificity to differentiate the risk of SCD from the risk of mortality associated with heart failure or other comorbidities. Moreover, since SCD can occur in patients with normal or mildly depressed ejection fraction, it is necessary to identify new markers to improve the prognostic stratification of SCD. Several studies that analyzed the ventricular arrhythmia substrate found that myocardial fibrosis plays an important role in the genesis of ventricular arrhythmias in patients with NIDCM. The surrounding zone of the area of fibrosis is a heterogeneous medium, where tissue with different levels of fibrosis coexists, resulting in both viable and nonviable myocardium. This myocardial fibrosis may constitute a substrate for ventricular arrhythmias, where slow and heterogeneous conduction may favor the genesis of reentry mechanism increasing the chance to develop sustained ventricular tachycardia or ventricular fibrillation. Therefore, the evaluation of ventricular fibrosis by late gadolinium enhancement (LGE) cardiac magnetic resonance imaging has been suggested as an indicator for SCD risk stratification. Indeed, LGE in patients with NIDCM is associated with increased risk of all-cause mortality, heart failure hospitalization, and SCD. Detection of myocardial fibrosis as LGE by cardiac magnetic resonance imaging can be considered as a useful pathway of prediction of malignant ventricular arrhythmias since it has excellent prognostic characteristics and may help guide risk stratification and management in patients with NIDCM.

Manejo terapéutico y diagnóstico en equipo multidisciplinario y resultados obtenidos en gestantes con cardiopatía orgánica / Diagnostic and therapeutic management and clinical outcome by a multidisciplinary team in pregnant women with heart disease

Las enfermedades cardiovasculares afectan aproximadamente al 2% de las mujeres embarazadas, por lo que suponen un aumento del riesgo tanto para la madre como para el feto. El embarazo y el parto producen cambios fisiológicos sustanciales que requieren de una adecuada adaptación del sistema cardiovascular. Estos cambios fisiológicos que son muy bien tolerados en las gestantes sin cardiopatía, exponen a la mujer con enfermedad cardiovascular a eventos clínicos significativos. Este es un trabajo descriptivo, retrospectivo, de casos consecutivos de pacientes que acudieron a la División de Medicina Cardiovascular, del Hospital de Clínicas en un período comprendido entre Agosto de 2013 a Junio de 2014. Incluye a 5 pacientes embarazas y portadoras de cardiopatías conocidas o desconocidas. La edad promedio fue de 27 años, rango etario de 17 a 36 años. La edad gestacional al momento de la consulta fue de 34 semanas por fecha de última menstruación, menor edad gestacional 30 semanas y mayor edad gestacional 38 semanas. El síntoma principal de consulta fue la disnea (100%), edema de miembros inferiores en 3 pacientes (60%), y palpitaciones en 2 pacientes (40%). El manejo diagnóstico y terapéutico conjunto con un seguimiento detallado y adecuado por un equipo multidisciplinario de cardiólogos, clínicos, ginecólogos, anestesiólogos y cirujanos cardiovasculares facilitan una buena evolución clínica y un desenlace exitoso del embarazo y parto de la gestante con la cardiopatía orgánica. Como resultado de este manejo multidisciplinario todos los recién nacidos tuvieron buena evolución durante su permanencia en la unidad de cuidados intensivos sin inconvenientes(AU)

Heart diseases affect approximately 2% of pregnant women increasing the risk of the mother and the child. The pregnancy and the delivery produce substantial physiological changes requiring an adequate adaptation of the cardiovascular system. These changes, which are well tolerated by pregnant women without heart disease, expose the pregnant women with heart disease to significant clinical events. This is a descriptive, retrospective study of consecutive cases in the Division of Cardiovascular Medicine of the Hospital de Clínicas between August 2013 and June 2014. It includes five pregnant women with known or unknown heart disease at the time of consultation. The average age was 27 years old (17 to 36 years old). The average gestational age was 34 weeks (30 to 38 weeks). The main symptom at consultation was dyspnea (100%), edema of inferior limbs (60%), and palpitations (40%). The joint diagnostic and therapeutic management with a detailed and adequate follow-up by a multidisciplinary team of cardiologists, physicians, gynecologists, anesthesiologists, and cardiac surgeons facilitated a good clinical outcome and a successful completion of the pregnancy and delivery of the pregnant women with heart disease. As a result of the work of this multidisciplinary team, all the newborns had good evolution during their stay at the intensive care unit without any difficulties(AU)

Conceptos actuales sobre la clasificación clínica y alteraciones electrofisiológicas en la disfunción del nódulo sinusal / Current concepts about the clinical classification and electrophysiological alterations in the sinus node dysfunction

La disfunción del nódulo sinusal (DNS) es generalmente secundaria a la senescencia del nodo sinusal y del miocardio auricular circundante. Los pacientes con este trastorno son a menudo añosos y en general presentan otras comorbilidades. Los pacientes a menudo buscan atención médica con síntomas de aturdimiento, pre-síncope, síncope y, en pacientes con periodos alternantes de bradicardia y taquicardia, palpitaciones u otros síntomas asociados con una frecuencia cardíaca rápida. Debido a que los síntomas pueden ser de naturaleza variable, inespecíficos y frecuentemente transitorios, a veces puede ser difícil establecer esta relación síntoma-alteración electrocardiográfica. Los hallazgos electrocardiográficos típicos son uno o más episodios de bradicardia sinusal extrema (Rubenstein Tipo I), o pausas sinusales, paro y bloqueo de salida sinoatrial (Rubenstein Tipo II), o episodios de bradicardia y/o pausas alternantes con taquiarritmias auriculares (Rubenstein Tipo III). Las investigaciones basadas en el registro de electrogramas locales auriculares anormalmente prolongados y fraccionados durante el ritmo sinusal y su distribución característica en la aurícula derecha de pacientes con DNS han aportado un conocimiento importante sobre las propiedades electrofisiológicas de la aurícula patológica. El electrograma auricular anormal traduce una conducción auricular irregular, caracterizada por una actividad eléctrica local no homogénea, relacionada con una conducción anisotrópica, no uniforme y retardada a través de un miocardio auricular patológico, en el que se pueden originar arritmias por reentrada. La detección de electrogramas auriculares anormales en la DNS identifica a un grupo de pacientes con vulnerabilidad auricular aumentada y con una incidencia significativamente mayor de episodios espontáneos o inducidos de fibrilación auricular(AU)

Sinus node dysfunction (SND) is often secondary to senescence of the sinus node and surrounding atrial myocardium. Patients with this disorder are frequently elderly and generally have other comorbidities. Patients with SND often seek medical attention with symptoms of lightheadedness, presyncope, syncope, and, in patients with alternating periods of bradycardia and tachycardia, palpitations and/or other symptoms associated with a rapid heart rate. Because symptoms may be variable in nature, nonspecific, and frequently transient, it may be challenging at times to establish this symptom-rhythm relationship. Typical electrocardiographic findings are one or more episodes of extreme sinus bradycardia (Rubenstein type I), or sinus pauses, arrest, and sinoatrial exit block (Rubenstein type II), or alternating bradycardia and atrial tachyarrhythmias (Rubenstein type III). Investigations based on the recording of abnormally prolonged and fractionated local atrial electrograms during sinus rhythm and their characteristic distribution in the right atrium of patients with SND have provided important knowledge about the pathological atrium electrophysiological properties. Abnormal atrial electrogram results in an irregular atrial conduction, characterized by a non-homogeneous local electrical activity, related to an anisotropic, non-uniform and delayed conduction through a pathological atrial myocardium, in which reentry arrhythmias may arise. Abnormal atrial electrograms detection in SND identifies a group of patients with increased atrial vulnerability and a significantly higher incidence of spontaneous or induced episodes of atrial fibrillation(AU)