Feasibility and safety of zero-fluoroscopy left bundle branch pacing: An initial experience.

INTRODUCTION: Left bundle branch pacing (LBBP) has emerged in recent years as a new pacing modality, providing patients with a narrower paced QRS than conventional pacing and stable pacing parameters. At the same time, there is a growing concern about the use of fluoroscopy in pacemaker implantations, given its harmful effects on both patients and operators. However, there are no prior experiences of zero-fluoroscopy in LBBP procedure. METHODS: We conducted an observational prospective study recruiting consecutive patients that underwent zero-fluoroscopy LBBP pacemaker implantation. A 6-month follow-up visit was programmed for every patient. The main goal of our study was to assess the efficacy, feasibility, and safety of the procedure. RESULTS: From January 2021 to February 2022, we included 10 patients, 8 males. The average age was 63 ± 4 years. The procedure was successful in all patients. We observed a significant reduction in paced QRS width compared with basal QRS width (149 ± 31.9 vs. 116 ± 15.6 ms, p = .02). All device parameters remained stable at 6-month follow-up: no significant differences in mean impedance (700.5 ± 136.4 vs. 494 ± 72.7 Ohm, p = .09), capture threshold (0.67 ± 0.2 vs. 0.83 ± 0.2 V @ 0.4 ms, p = .27) or endocardial V-wave amplitude (10.6 ± 5.2 vs. 13.9 ± 6.3 mV, p = .19). No complications were reported in any case. CONCLUSION: Zero-fluoroscopy LBBP is feasible and safe, and it may be considered in cases where radiation exposure is contraindicated or especially undesirable. Future randomized clinical trials are needed for the widespread use of this new technique.

Echocardiographic markers of cardiac amyloidosis in patients with heart failure and left ventricular hypertrophy.

BACKGROUND: Cardiac amyloidosis (CA), following a non-invasive diagnosis, constitutes an increasingly prevalent heart failure (HF) etiology. This study aims to determine which echocardiography findings help to diagnose CA in patients with left ventricular hypertrophy (LVH) admitted for decompensated HF. METHODS: The present study is a retrospective observational study on a cohort of 85 LVH patients admitted for HF decompensation, in which 99mTc-DPD scanning was performed to rule out transthyretin CA. The echocardiographic findings obtained were compared between CA and non-CA groups. RESULTS: From a total number of 85 patients, 49 (57.6%) met the CA criteria and 36 (42.3%) were ruled out for the disease. Interventricular septum thickness (16 ± 3 mm vs. 14 ± 3 mm), left ventricular posterior wall thickness (14 ± 3 mm vs. 11 ± 2 mm), left ventricular mass (259 ± 76 g vs. 224 ± 53 g), left ventricular end-diastolic diameter (48 ± 7 mm vs. 53 ± 6 mm), left ventricular end-diastolic indexed volume (51 ± 18 cm3/m2 vs. 59 ± 16 cm3/m2), tricuspid annular plane systolic excursion (16 ± 5 mm vs. 20 ± 4 mm), right atrial area (27.4 ± 8.4 cm2 vs. 22.2 ± 5.7 cm2) and strain relative apical sparing (2.2 ± 0.9 vs. 1.03 ± 0.4; p = 0.04) were significantly associated with the diagnosis of CA. CONCLUSIONS: In patients with LVH admitted for HF decompensation, there are several echocardiographic features (LVH, reduced left ventricular cavity size, strain relative apical sparing, right atrial dilation, and altered right ventricular function) that are associated with the diagnosis of cardiac amyloidosis.

Local impedance and contact force guidance to predict successful cavotricuspid isthmus ablation with a zero-fluoroscopy approach.

Introduction: A new technology capable of monitoring local impedance (LI) and contact force (CF) has recently been developed. At the same time, there is growing concern regarding catheter ablation performed under fluoroscopy guidance, due to its harmful effects for both patients and practitioners. The aim of this study was to assess the safety and effectiveness of zero-fluoroscopy cavotricuspid isthmus (CTI) ablation monitoring LI drop and CF as well as to elucidate if these parameters can predict successful radiofrequency (RF) applications in CTI ablation. Methods: We conducted a prospective observational study recruiting 50 consecutive patients who underwent CTI ablation. A zero-fluoroscopy approach guided by the combination of LI drop and CF was performed. In each RF application, CF and LI drop were monitored. A 6-month follow-up visit was scheduled to assess recurrences. Results: A total of 767 first-pass RF applications were evaluated in 50 patients. First-pass effective RF applications were associated with greater LI drops: absolute LI drops (30.05 ± 6.23 Ω vs. 25.01 ± 5.95 Ω), p = 0.004) and relative LI drops (-23.3 ± 4.9% vs. -18.3 ± 5.6%, p = 0.0005). RF applications with a CF between 5 and 15 grams achieved a higher LI drop compared to those with a CF below 5 grams (29.4 ± 8.76 Ω vs. 24.8 ± 8.18 Ω, p < 0.0003). However, there were no significant differences in LI drop between RF applications with a CF between 5 and 15 grams and those with a CF beyond 15 grams (29.4 ± 8.76 Ω vs. 31.2 ± 9.81 Ω, p = 0.19). CF by itself, without considering LI drop, did not predict effective RF applications (12.3 ± 7.54 g vs. 11.18 ± 5.18 g, p = 0.545). Successful CTI ablation guided by a zero-fluoroscopy approach was achieved in all patients. Only one patient experienced a recurrence during the 6-month follow-up. Conclusions: LI drop (absolute and relative values) appears to be a good predictor of successful RF applications to achieve CTI conduction block. The optimal CF to achieve a good LI drop is between 5 and 15 g. A zero-fluoroscopy approach guided by LI and CF was feasible, effective, and safe.

Coexistence of Positive 99mTc-DPD Scintigraphy and Monoclonal Gammopathy: A Frequent Challenge.

Background: Cardiac involvement is common in amyloidosis, and the vast majority of cases of amyloid cardiomyopathy are attributed to primary amyloidosis or transthyretin amyloidosis (ATTR). Although the coexistence of scintigraphy suggestive of ATTR with monoclonal gammopathy of undetermined significance is well documented, the correct diagnosis is still challenging in non-referral centers. Methods: We performed a retrospective study reviewing all amyloid cardiomyopathy cases diagnosed at our center over the last 5 years, and described our experience and diagnostic approach. Results: During the last 5 years, 74 patients with positive scintigraphy were identified. Of these patients, 41 were included in this study as they had all necessary tests for a complete diagnosis. Two of these 41 patients had variant ATTR and 29 had wild-type ATTR. Ten patients had monoclonal gammopathy (24.4%), and it was consequently impossible to obtain a specific diagnosis. During follow-up, 14 patients (34.1%), five of them from the monoclonal gammopathy group, died, reflecting the severity of disease. Conclusions: In patients with ATTR-suggestive scintigraphy, monoclonal gammopathy frequently occurs concomitantly, thus not allowing to establish a specific diagnosis. A biopsy could only be replaced by genetic testing in selected cases.

[Anatomy variant of the papillary muscles as a cause of mitral regurgitation. Case report of a parachute-like asymmetric mitral valve] / Variante de la anatomía de los músculos papilares como causa de insuficiencia mitral. Un caso de válvula mitral asimétrica en paracaídas-like.

Introducción: La válvula mitral en paracaídas-like es una anomalía congénita caracterizada por una disposición asimétrica de los músculos papilares, siendo las pruebas de imagen cardiaca son el procedimiento de elección tanto para el diagnóstico anatómico como para realizar la valoración funcional de este tipo de anomalía estructural. Caso Clínico: Paciente con cuadro de descompensación hemodinámica en el cual se diagnóstica de manera incidental de una valvulopatía mitral en forma de paracaídas-like. Los hallazgos de imagen por ecocardiografía transtorácica y resonancia magnética ponen de manifiesto la presencia de 2 músculos papilares, ambos con inserción en segmento lateral apical confirmando una válvula mitral asimétrica con similitud a su morfología en paracaídas. Discusión: La válvula mitral en paracaídas es una anomalía congénita poco común constituyente en la presencia de dos músculos papilares siendo uno de ellos más elongado y adherido al velo mitral de forma contigua, mostrándose en algunos casos pequeñas cuerdas tendinosas asociadas. Puede presentar una evolución benigna siendo un hallazgo casual o asociarse a repercusión hemodinámica valvular como el caso presentado. Conclusión: La válvula mitral en paracaídas-like es una anomalía congénita caracterizada por una disposición asimétrica de los músculos papilares, siendo su evolución muy variable, pudiendo pasar desapercibida o afectando de forma significativa a la mecánica valvular.

Introducción: La válvula mitral en paracaídas-like es una anomalía congénita caracterizada por una disposición asimétrica de los músculos papilares, siendo las pruebas de imagen cardiaca son el procedimiento de elección tanto para el diagnóstico anatómico como para realizar la valoración funcional de este tipo de anomalía estructural. Caso Clínico: Paciente con cuadro de descompensación hemodinámica en el cual se diagnóstica de manera incidental de una valvulopatía mitral en forma de paracaídas-like. Los hallazgos de imagen por ecocardiografía transtorácica y resonancia magnética ponen de manifiesto la presencia de 2 músculos papilares, ambos con inserción en segmento lateral apical confirmando una válvula mitral asimétrica con similitud a su morfología en paracaídas. Discusión: La válvula mitral en paracaídas es una anomalía congénita poco común constituyente en la presencia de dos músculos papilares siendo uno de ellos más elongado y adherido al velo mitral de forma contigua, mostrándose en algunos casos pequeñas cuerdas tendinosas asociadas. Puede presentar una evolución benigna siendo un hallazgo casual o asociarse a repercusión hemodinámica valvular como el caso presentado. Conclusión: La válvula mitral en paracaídas-like es una anomalía congénita caracterizada por una disposición asimétrica de los músculos papilares, siendo su evolución muy variable, pudiendo pasar desapercibida o afectando de forma significativa a la mecánica valvular.

Cardiac Transthyretin Amyloidosis: A Nuclear Medicine Leading Role. Situation in a Spanish Center and "State of the Art" in Nuclear Medicine.

PURPOSE: Amyloidosis is a heterogeneous group of diseases caused by abnormal extracellular deposition of insoluble proteins and can involve myocardium. One of the causes of myocardial involvement is TTR amyloidosis. Our objective has been to evaluate the situation of cardiac amyloidosis (CA) in our center and the role of nuclear medicine, and to review the state of the art of nuclear medicine in this entity. PATIENTS AND METHODS: We have evaluated retrospectively 186 patients with clinical suspicion of CA and analyzed the clinical characteristics, free light chains and immunofixation in serum and/or urine, and the most relevant biomarkers associated with transthyretin CA (C-ATTR) of these patients and compared them with the results of the 99mTc-DPD scintigraphy. RESULTS: We have verified the growing bibliographic evidence concerning C-ATTR. A total of 51 scintigraphies (27.4%) were positive, 2 (1.1%) indeterminate and 133 (71.5%) negative according to the Perugini score. ATTR was diagnosed in 22 (11.8%; 77.3% males; mean age, 79.4 years). Of these, 12 (75% men; 82.3 years) were ATTRwt (wild-type or age-associated) patients, 2 (50% men; 52 years) experienced ATTRv (variant or hereditary), and 8 (87.5% men; 82.3 years) were not classified because of the absence genetic test. The origin of amyloidosis could not be determined in 31 (16.7%; 80.7% males; 84.5 years). In 29 of them (93.6%), it was because there was no study of free light chains or immunofixation. CONCLUSIONS: Nuclear medicine is playing an increasing role in the diagnosis and classification of CA. However, the monitoring of these is still patchy.