His bundle pacing success and electrical parameter stability regardless of three-dimensional transthoracic echocardiography lead localization.

BACKGROUND OR PURPOSE: His bundle pacing (HBP) is the most physiological form of ventricular pacing. Few prospective studies have analyzed lead localization using imaging techniques and its relationship with electrical parameters and capture patterns. The objective of this study is to examine the correlation between electrical parameters and lead localization using three-dimensional transthoracic echocardiography (3D TTE). METHODS: This single-center, prospective, nonrandomized clinical research study (January 2018 to June 2020) included patients with an indication of permanent pacing, in whom 3D TTE was performed to define lead localization as supravalvular or subvalvular. RESULTS: A total of 92 patients were included: 56.5% of leads were supravalvular, and 43.5% were subvalvular, which resembles previous anatomic descriptions of autopsied hearts of His bundle localization within the triangle of Koch (ToK). R-wave sensing was higher when the His lead was localized subvalvular instead of supravalvular. His lead localization was not associated with HBP threshold or impedance differences, nor with the two different HBP patterns of capture, or with the ability of HBP to correct baseline BBB. The thresholds remained stable during follow-up visits, regardless of His lead localization. Higher R-wave sensing was observed during follow-up than at baseline, mainly in the subvalvular His leads. However, lead impedances in both positions decreased during follow-up. CONCLUSIONS: Lead localization in relation to the tricuspid valve did not influence the electrical performance of HBPs. Wide anatomical variations of the His bundle within the ToK explain our findings, reinforcing the idea that the technique for HBP should be fundamentally guided by electrophysiological and not anatomical parameters.

Improvement in electrocardiographic parameters of repolarization related to sudden death in patients with ventricular dysfunction and left bundle branch block after cardiac resynchronization through His bundle pacing.

BACKGROUND: Cardiac resynchronization therapy (CRT) through permanent His bundle pacing (p-HBP) normalizes interventricular conduction disorders and QRS. Similarly, there are immediate and long-term changes in repolarization, which could be prognostic of a lower risk of sudden death (SD) at follow-up. We aimed to compare the changes in different electrocardiographic (ECG) repolarization parameters related to the risk of SD before and after CRT through p-HBP. METHODS: In this prospective, descriptive single-center study (May 2019 to December 2021), we compared the ECG parameters of repolarization related to SD in patients with non-ischemic dilated cardiomyopathy, left bundle branch block (LBBB), and CRT indications, at baseline and after CRT through p-HBP. RESULTS: Forty-three patients were included. Compared to baseline, after CRT through p-HBP, there were immediate significant changes in the QT interval (ms): 445 [407.5-480] vs 410 [385-440] (p = 0.006), QT dispersion (ms): 80 [60-100] vs 40 [40-65] (p < 0.001), Tp-Te (ms): 90 [80-110] vs 80 [60-95] (p < 0.001), Tp-Te/QT ratio: 0.22 [0.19-0.23] vs 0.19 [0.16-0.21] (p < 0.001), T wave amplitude (mm): 6.25 [4.88-10] vs - 2.5 [- 7-2.25] (p < 0.001), and T wave duration (ms): 190 [157.5-200] vs 140 [120-160] (p = 0.001). In the cases of the corrected QT (Bazzett and Friederichia) and the Tp-Te dispersion, changes only became significant at 1 month post-implant (468.5 [428.8-501.5] vs 440 [410-475.25] (p = 0.015); 462.5 [420.8-488.8] vs 440 [400-452.5] (p = 0.004), and 40 [30-52.5] vs 30 [20-40] (p < 0.001), respectively) (Table 1). Finally, two parameters did not improve until 6 months post-implant: the rdT/JT index, 0.25 [0.21-0.28] baseline vs 0.20 [0.19-0.23] 6 months post-implant (p = 0.011), and the JT interval, 300 [240-340] baseline vs 280 [257-302] 6 months post-implant (p = 0.027). Additionally, most of the parameters continued improving as compared with immediate post-implantation. CONCLUSIONS: After CRT through His bundle pacing and LBBB correction, there was an improvement in all parameters of repolarization related to increased SD reported in the literature.

Spontaneous Coronary Artery Dissection and Hypothyroidism.

INTRODUCTION AND OBJECTIVES: Thyroid hormone affects the metabolism of all tissues in the body. The aim of this study was to analyze the prevalence and implications of thyroid disorders in a cohort of consecutive patients with spontaneous coronary artery dissection (SCAD). METHODS: A total of 73 patients with SCAD were analyzed. Baseline characteristics and clinical outcomes were compared between euthyroid and hypothyroid patients. Subsequently, the prevalence of thyroid function abnormalities and the clinical characteristics of SCAD patients were compared with those in 73 patients with acute coronary syndrome but without SCAD, matched by age, sex, and presentation. RESULTS: Mean age was 55 ± 12 years and 26% had hypothyroidism. Compared with patients with normal thyroid function, patients with SCAD and hypothyroidism were all women (100% vs 69%, P = .01), more frequently had dissection in distal (74% vs 41%, P = .03) and tortuous coronary segments (68% vs 41%, p = .03), and more frequently received conservative medical management (79% vs 41%, P = .007). During a mean clinical follow-up of 4.1 ± 3.8 years, 23% of the patients had adverse cardiac events irrespective of thyroid function status. The prevalence of hypothyroidism was higher in patients with SCAD than in matched patients with acute coronary syndrome without SCAD (26% vs 8%, P = .004). CONCLUSIONS: There is a high prevalence of hypothyroidism in patients with SCAD. Patients with SCAD and hypothyroidism are more frequently women, more frequently have distal dissections in tortuous vessels, and are more frequently managed with a conservative medical strategy.

Abluminal Neointimal Healing by Optical Coherence Tomography Assessment After Drug-Eluting Stent Implantation on Organized Recanalized Thrombus.

Six-month PCI follow-up results of left anterior descending (LAD) and circumflex (CX) drug-eluting stent implantation are presented. Angiography showed patent LAD and CX stents. However, OCT revealed almost all abluminal cavities were completely filled, which the authors surmise was due to a neointimal healing process.

Radial/Ulnar angioplasty in selected patients undergoing elective angiography or PCI using complex forearm approach.

BACKGROUND: Angioplasty on the radial artery have been performed with good success rates in patients with critical hand ischemia. We sought to assess the feasibility and safety of radial angioplasty on complex radial access in patients undergoing coronary angiography. METHODS/MATERIAL: A prospective series of procedures with complex radial/ulnar access to which radial-ulnar angioplasty (RU-A) was performed. We set goals of efficacy and safety that included the success rate of the procedure (need for ¨Crossover femoral¨) and the existence of radial pulse at one month. RESULTS: 18 cases of RU-A out of 11,500 procedures from March 2010 to July 2016 (0.15%) were included. The majority of the patients were men with a variety of cardiovascular risk factors (age 71±9; 94% Hypertensive, 56% Diabetic, 18% chronic kidney disease). The most common indication for radial/ulnar angioplasty was severe arteriosclerotic stenosis. Angioplasty was performed with different types of over the wire peripheral balloons (Mean diameter 4,3±1 and mean length 42±15mm), in one case a stent implantation was needed. The success rate was 100% without vascular complications at 1-month clinical and vascular doppler follow-up. CONCLUSIONS: Radial/ulnar artery angioplasty is feasible and safe in selected patients undergoing elective angiography or percutaneous coronary intervention using complex forearm approach.

Detection of spontaneous coronary artery spasm with optical coherence tomography in a patient with acute coronary syndrome.

We present 2 illustrative cases of acute coronary syndrome and spontaneous coronary artery spasm evaluated by optical coherence tomography. Different spasm patterns were showed by optical coherence tomography (OCT), according to whether there were underlying atherosclerotic plaques or not.

Bioresorbable Scaffolds in Spontaneous Coronary Artery Dissection: Long-Term Follow-Up in 4 Patients.

Spontaneous coronary artery dissection is a rare condition, and diagnosis and treatment are challenging among patients who present with acute coronary syndrome. Typically, the condition affects young females who have no underlying atherosclerotic disease. To date, few cases of bioresorbable scaffold implantation for the treatment of spontaneous coronary artery dissection have been reported. Therefore, we describe the cases of 4 patients whom we treated with scaffolds. We evaluated the long-term results by using intravascular ultrasound and optical coherence tomographic scanning.

Utility of 3D-OCT Imaging With Angiographic Co-Registration in Acute Coronary Syndrome With Normal or Near-Normal Coronary Arteries.

The OPTIS integrated system (St. Jude Medical) is a new technology allowing the online co-registration of optical coherence tomography (OCT) images with the angiogram in the catheterization laboratory. Additionally, 3D navigation can be performed. This integration of OCT information on an angiographic roadmap could find broad application in the characterization of substrates causing acute coronary syndromes with normal or near-normal coronary arteries. The utility of OCT with co-registration for the guidance of percutaneous coronary intervention could be considerable in the management of patients with acute coronary syndromes.

The Absorb Limits.

A patient presented with an inferior non-ST segment elevation myocardial infarction and a tight lesion on the distal right coronary artery. After stent implantation, a large scaffold malapposition was observed by optical coherence tomography. This case emphasizes the importance of not expanding a bioresorbable vascular scaffold more than 0.5 mm over its nominal size.