Cardiac resynchronization therapy (CRT) represents an increasingly recommended solution to alleviate symptomatology and improve the quality of life in individuals with dilated cardiomyopathy (DCM) and heart failure (HF) with reduced ejection fraction (HFrEF) who remain symptomatic despite optimal medical therapy (OMT). However, this therapy does have the desired results all cases, in that sometimes low sensing and high voltage stimulation are needed to obtain some degree of resynchronization, even in the case of perfectly placed cardiac pacing leads. Our study aims to identify whether there is a relationship between several transthoracic echocardiographic (TTE) parameters characterizing left ventricular (LV) performance, especially strain results, and sensing and pacing parameters. Between 2020–2021, CRT was performed to treat persistent symptoms in 48 patients with a mean age of 64 (53.25–70) years, who were diagnosed with DCM and HFrEF, and who were still symptomatic despite OMT. We documented statistically significant correlations between global longitudinal strain, posterolateral strain, and ejection fraction and LV sensing (r = 0.65, 0.469, and 0.534, respectively, p < 0.001) and LV pacing parameters (r = −0.567, −0.555, and −0.363, respectively, p < 0.001). Modern imaging techniques, such as TTE with cardiac strain, are contributing to the evaluation of patients with HFrEF, increasing the chances of CRT success, and allowing physicians to anticipate and plan for case management.

(1) Background: Cardiac resynchronization therapy (CRT) systems can be simplified by excluding the atrial lead and using a Ventricular-Dual-Dual (VDD) pacing lead. Possible disadvantages might include atrial undersensing and Ventricular-Ventricular-Inhibition (VVI) pacing. Because literature data concerning these systems are scarce, we analyzed their benefits and technical safety. (2) Methods: this retrospective study compared 50 patients implanted with VDD–CRT systems (group A), mainly because of unfavorable venous anatomy concerning the complication rate, with 103 subjects with Dual-Dual-Dual (DDD)–CRT systems (group B) implanted during 2000–2016 and 49 (group C) during 2016–2020. To analyze the functional parameters of the devices, we selected subgroups of 27 patients (subgroup A) and 47 (subgroup B) patients with VDD–CRT in 2000–2016, and 36 subjects (subgroup C) with DDD–CRT implanted were selected in 2017–2020. (3) Results: There was a trend of a lower complication rate with VDD–CRT systems, especially concerning infections during 2000–2016 (p = 0.0048), but similar results were obtained after rigorous selection of patients and employment of an upgraded design of devices/leads. With a proper device programing, CRT pacing had similar results, atrial undersensing being minimal (p = 0.65). For VDD-systems, VVI pacing was recorded only 1.7 ± 2.24% of the time. (4) Conclusions: In patients with a less favorable venous anatomy, VDD–CRT systems may represent a safe alternative regarding complications rates and functional parameters.

Funding Acknowledgements Type of funding sources: None. Background. Reactive oxygen species (ROS) have been reported to contribute to the molecular pathogenesis of severe mitral regurgitation induced by myxomatous degeneration. Data about oxidative stress and the possible relationship with the extent of prolapsing and/or flail elements is scarce in the literature. The pathogenic mechanism may prompt the development of therapeutic approaches aimed at delaying extensive valvular alteration. Purpose. The aim of the study is to investigate the possible correlation between ROS expression in myxomatous mitral valves with severe regurgitation and the extent of valvular alteration. Material and methods. Samples from myxomatous mitral valves with ruptured chordae and severe regurgitation were harvested during surgical intervention for valve repair/replacement from 9 patients. Besides transthoracic echocardiography, all patients were evaluated before surgery by transesophageal echocardiography (TEE) with three-dimensional (3D) reconstruction of the mitral valve, using 3D zoom mode acquisition with qualitative and quantitative analysis through the 4D Auto MVQ technology. Tissue from the valvular samples was further analysed for the assessment of ROS by 2 methods: spectrophotometry (ferrous oxidation xylenol orange - FOX assay) and confocal microscopy (dihydroethidium staining). Results. Patients had a mean age of 51.88 ± 13.54 years, with a left ventricular ejection fraction of 62.55 ± 7.33%, left ventricular end-diastolic diameter of 5.4 ± 0.72cm and end-diastolic volume of 168.55 ± 62.57ml, a mitral annulus area of 17.91 ± 5.74 cm2 and a number of prolapsing/flail scallops varying between 1 and 5 (average of 2 ± 1 scallops). All patients had diffuse thickening of the mitral leaflets with at least one primary and one secondary ruptured chordae and flail of the P2 scallop. Two patients had significant prolapse of at least 2 anterior mitral leaflet scallops and three patients had supplemental significant prolapse and/or flail of at least 1 posterior scallop, besides flail of P2. The mean value for ROS in the valvular tissue was 9.46 ± 2.03nM H2O2/mg tissue/h at FOX assay. A significant positive correlation between the ROS values and the extent of prolapsing/flail segments was found (R = 0.67, p = 0.04). Conclusion. Besides the diagnosis and accurate preoperatory valve description, 3D TEE along with molecular investigations contribute to the understanding of myxomatous mitral valves’ pathogenesis. Oxidative stress increased in the mitral valves with advanced myxomatous degeneration. Whether this occurs as a cause or a consequence contributing to the disease progression as well as the sources of ROS are worth further investigation.