Intermuscular implantation technique for subcutaneous cardioverter-defibrillators.

BACKGROUND: The conventional technique for subcutaneous implantable cardioverter-defibrillator (S-ICD) implantation has been associated with pocket complications. The aim of this study was to evaluate the efficacy and safety of an alternative intermuscular technique for S­ICD implantation. METHODS: S-ICDs were implanted in ten consecutive patients (ten males, mean age: 46.8 ± 14.7 years). The pocket for the pulse generator was made above the serratus anterior muscular fascia and beneath the latissimus dorsi muscle by detaching the fibrous tissue between the muscles. Electrode implantation was performed using the three- (n = 4) or the two-incision technique (n = 6). RESULTS: All S­ICDs were successfully implanted in the absence of any procedure-related complications with a successful 65-J standard polarity defibrillation threshold testing, apart from one patient with Brugada syndrome who needed device repositioning more dorsally. During a mean follow-up of 16.5 ± 7.3 months, no major complications requiring surgical repair were encountered, while patients demonstrated high levels of comfort and satisfaction with the cosmetic result. One patient experienced an inappropriate shock due to noise detection, which was resolved after reprogramming to a different sensing vector. CONCLUSION: The intermuscular technique is a safe and efficacious approach for S­ICD implantation. This technique could lead to fewer pocket-related complications and better cosmetic results.

The association of hematological indices with the response to cardiac resynchronization therapy: a single-center study.

BACKGROUND: Cardiac resynchronization therapy (CRT) is an established therapeutic option for patients with heart failure (HF) and left ventricular ejection fraction (LVEF) ≤35 % who meet specific criteria according to current guidelines. However, up to 40 % of patients have no response to CRT. Our study aimed to investigate the association between different hematological and biochemical indices and response to CRT. METHODS: Patients with HF due to ischemic or dilated cardiomyopathy referred to our hospital for CRT implantation from January 2013 to November 2017 were included in the study. Response to CRT was defined as an increase in LVEF ≥10 % or a decrease in left ventricular end-systolic volume (LVESV) ≥15 % at six months of follow-up. RESULTS: A total of 48 patients (mean age: 66.2 ± 9.5 years, 81.3 % males) were included in the study. Of these HF patients, 29 (60.4 %) had ischemic cardiomyopathy, and 19 (39.6 %) had dilated cardiomyopathy. At six months of follow-up, 37 patients (77.1 %) had responded to CRT. Ten patients (20.8 %) had ventricular tachycardia (VT), 24 (50 %) patients were hospitalized, and two patients (4.2 %) died during the follow-up period. Multivariate analysis demonstrated that age (p =0.03) and creatinine levels (p =0.02) were independent predictors of the response to CRT. No significant associations between hematological markers (white blood cells, neutrophils, lymphocytes, platelets, neutrophil to lymphocyte ratio, red blood cells distribution width) and CRT response were observed. CONCLUSIONS: A smaller increase in LVEF and a smaller decrease in LVESV were predictive for VT occurrence and hospitalizations in patients receiving CRT. No significant association between hematological markers and response to CRT was found. HIPPOKRATIA 2019, 23(3): 118-125.

Impact of baseline renal function on all-cause mortality in patients who underwent cardiac resynchronization therapy: A systematic review and meta-analysis.

BACKGROUND: Cardiac resynchronization therapy (CRT) improves both morbidity and mortality in selected patients with heart failure and increased QRS duration. However, chronic kidney disease (CKD) may have an adverse effect on patient outcome. The aim of this systematic review was to analyze the existing data regarding the impact of baseline renal function on all-cause mortality in patients who underwent CRT. METHODS: Medline database was searched systematically, and studies evaluating the effect of baseline renal function on all-cause mortality in patients who underwent CRT were retrieved. We performed three separate analyses according to the comparison groups included in each study. Data were analyzed using Review Manager software (RevMan version 5.3; Oxford, UK). RESULTS: We included 16 relevant studies in our analysis. Specifically, 13 studies showed a statistically significant higher risk of all-cause mortality in patients with impaired baseline renal function who underwent CRT. The remaining three studies did not show a statistically significant result. The quantitative synthesis of five studies showed a 19% decrease in all-cause mortality per 10-unit increment in estimated glomerular filtration rate (eGFR) [HR: 0.81, 95% CI (0.73-0.90), p<0.01, 86% I2]. Additionally, we demonstrated that patients with an eGFR<60 mL/min/1.73 m2 had an all-cause mortality rate of 66% [HR: 1.66, 95% CI (1.37-2.02), p<0.01, 0% I2], which was higher than in those with an eGFR≥60 mL/min/1.73 m2. CONCLUSION: Baseline renal dysfunction has an adverse effect on-all cause mortality in patients who underwent CRT.

5-fluorouracil cardiotoxicity is a rare, dose and schedule-dependent adverse event: a prospective study.

PURPOSE: Cardiotoxicity associated with 5-fluorouracil (5FU) administration is infrequently reported in the literature, albeit case reports of acute coronary syndromes have been published. In the present study, patients undergoing 5FU chemotherapy were tested for the development of cardiac-related symptoms during its administration. PATIENTS AND METHODS: Five hundred twenty-two patients entered the study. Those experiencing any cardiac-related symptoms during 5FU infusion were subjected to electrocardiogram (ECG) and serum cardiac enzymes determination. If cardiotoxicity was confirmed, 5FU infusion was interrupted, sublingual nitrates administered and cardiac monitoring initiated, while patients with >2-fold enzyme elevation were admitted into a coronary care unit for at least 72 hours. Cases with acute myocardial infarction had to discontinue 5FU treatment. RESULTS: Overall 20 (3.8%) patients developed symptoms and/or ECG abnormalities due to 5FU. Patients with continuous 5FU infusion had a trend for higher incidence of cardiotoxicity (13/205, 6.3%) than the remaining (7/317, 2.2%; p=0.067). More specifically, increased toxicity was encountered in patients with continuous 24 h 5FU+ leucovorin (LV) infusion for 5 days compared to patients with the same schedule without LV (p <0.027) and patients with short 5FU+LV administration as well (p=0.024). Seven out of the 20 patients suffered acute myocardial infarction, 6 developed only ischemia, while ECG findings consistent with coronary vasospasm were detected in 4 patients and conduction disturbances in 3 patients (one subsequently died). CONCLUSION: The present study indicates a toxic effect of 5FU on myocardium, which is largely schedule-dependent. High level of alert is required when using this drug, while its toxic effect on the coronary endothelium and myocardium merits further investigation.

Effect of atrial pressure increase on effective refractory period and vulnerability to atrial fibrillation in patients with lone atrial fibrillation.

BACKGROUND: There is evidence suggesting that atrial fibrillation (AF) may be induced by acute increase of atrial pressure. The aim of the present study was to investigate the effect of alterations in atrial pressure, induced by varying the atrioventricular (AV) interval, on atrial refractoriness, and on the frequency of induction of (AF), in patients with a history of lone atrial fibrillation (LAF). METHODS AND RESULTS: Twenty-five patients were included in this study. The patients were divided in two groups: the LAF group, and the control group. None of the patients in either group had organic heart disease. Effective refractory period (ERP) and duration of atrial extrastimulus electrogram (A(2)) were measured at two right atrial sites (high lateral wall, atrial appendage) during AV pacing (cycle length: 500 msec) with different AV intervals. Peak, minimal and mean atrial pressure increased from 8.57 +/- 2.37 to 18.14 +/- 4.74 mm Hg, 2 +/- 2.23 to 5.14 +/- 2.60 mm Hg (p = 0.0001) and from 4.28 +/- 1.6 mm Hg to 9.77 +/- 2.9 mm Hg (p = 0.001), respectively during AV interval modification. During lateral and atrial appendage pacing, with a progressive decrease of AV interval to 160, 100, 80, 40, 0 msec, the ERP, the dispersion of ERP, functional refractory period (FRP), A2 and latency period (LP) did not change significantly, in both groups. The frequency of induction of AF was not statistically different in both lateral atrial wall and appendage, during pacing in different AV intervals. CONCLUSIONS: This study demonstrates that alterations in the intraatrial pressure does not have important effects on atrial refractoriness and does not increase vulnerability to AF in patients with a history of LAF.

Intracoronary stent placement proximal to a myocardial bridge: immediate and long-term results.

The intracoronary stent placement in a lesion proximal to a myocardial bridge is of special importance and is considered to be a challenge for the interventional cardiologist. In this study 4 cases of stent implantation proximal to a coronary bridged segment are described. In all cases complications were observed after the procedure. The patients remained free of symptoms and the exercise TI201 test was negative for ischemia 8.5+/-2.6 months later. Although there is skepticism because of the abnormal coronary flow pattern, the endothelial dysfunction and the subsequent thrombogenicity, the stent placement proximal to a myocardial bridge was safe and with favorable long term results in all 4 cases. However, further studies in large populations are necessary.

Excessive sinus pauses and their elimination in a patient with sleep apnea syndrome.

A 40-year-old man with severe sleep apnoea syndrome presented significant sinus pauses during a 48 h electrocardiogram Holter recording. Holter analysis showed one sinus pause of 6.4 s duration, and many pauses greater than 3 s. The 48 h Holter reevaluation, after a continuous positive air pressure device was applied, showed no pauses. The electrophysiological study was negative for sick sinus syndrome.