Determining the recurrence rate of premature ventricular complexes and idiopathic ventricular tachycardia after radiofrequency catheter ablation with the help of designing a machine-learning model.

Ventricular arrhythmias increase cardiovascular morbidity and mortality. Recurrent PVCs and IVT are generally considered benign in the absence of structural heart abnormalities. Artificial intelligence is a rapidly growing field. In recent years, medical professionals have shown great interest in the potential use of ML, an integral part of AI, in various disciplines, including diagnostic applications, decision-making, prognostic stratification, and solving complex pathophysiological aspects of diseases from these data at extraordinary complexity, scale, and acquisition rate. The aim of this study was to design an ML model to predict the probability of PVC and IVT recurrence after RF ablation. Data of patients were collected and manipulated using traditional analysis and various artificial intelligence models, namely MLP, Gradient Boosting Machines, Random Forest, and Logistic Regression. Hypertension, male sex, and the use of non-irrigate catheters were associated with less freedom from arrhythmia. All these results were obtained through traditional analytic methods, and according to AI, none of the variables had a clear effect on the recurrence of arrhythmia. Each AI model presents unique strengths and weaknesses, and further optimization and fine-tuning of these models are necessary to increase their clinical utility. By expanding the dataset, improved predictions can be fostered to ultimately increase the clinical utility of AI in predicting PVC erosion outcomes.

Endocardial pacing in a single-ventricle patient with tricuspid atresia-a case report.

Key Clinical Message: The use of endocardial pacing in patients with univentricular hearts and intracardiac shunts is limited, primarily due to the increased risk of thromboembolism. However, when accompanied by proper long-term anticoagulation therapy, it may be safer than epicardial interventions in selected patients at high risk for surgery. Abstract: We report transvenous endocardial pacing through the atrial septal defect in a patient with tricuspid atresia, transposition of the great arteries, severe pulmonary hypertension, and complete heart block. This study is among the first reported cases using this pacing method in a patient with a univentricular heart and intracardiac shunt.

Evaluation of in-hospital NT-proBNP changes in heart failure patients to identify the six-month clinical response following cardiac resynchronization therapy.

N-terminal pro ß-type natriuretic peptide (NT-proBNP) is a valuable marker for monitoring the response to treatment in patients with heart failure. Based on the clinically observed improvement of heart failure symptoms early after cardiac resynchronization therapy (CRT), we sought to investigate whether CRT induce any significant reduction in the plasma level of NT-proBNP in three days after implantation and whether it is correlated with patients' response at six months. In this prospective study, 21 consecutive patients with severe heart failure (New York Heart Association class 3.19±0.40) who underwent CRT were enrolled. Being alive, no hospitalization due to decompensated heart failure, and improvement of at least one NYHA functional class at six months were classified as clinical responsiveness. The plasma level of NT-proBNP was measured before, three days, and six months after CRT. Clinical evaluation, echocardiographic study, and six-minute walking test were performed before and six months after the procedure. At six months' follow-up, 16 (76.2%) patients were responders. The plasma level of NT-proBNP at three days after CRT increased almost equally in both responder and non-responder groups of patients (∆NT-proBNP was 40.94±135.74 vs. 54.80±88.98); however, at six months' follow-up, the NT-proBNP changes statistically differed across the two groups of patients (P=0.005). According to our findings, NT-proBNP percent deviation from baseline to three days after CRT appears to be not correlated with the patients' clinical response after six months, which was incongruent to the patients' clinical improvement after CRT.

Cardiac autonomic neuropathy measured by heart rate variability and markers of subclinical atherosclerosis in early type 2 diabetes.

Cardiac autonomic neuropathy (CAN) is a critical complication of type 2 diabetes mellitus (T2DM). Heart rate variability (HRV) is a noninvasive tool to assess cardiac autonomic function. We aimed to evaluate whether CAN is associated with increased risk of atherosclerosis in T2DM. A total of 57 diabetic and 54 nondiabetic subjects, free of coronary heart disease, were recruited. Carotid intima media thickness (CIMT), coronary calcium score (CAC), and brachial Flow Mediated Dilation (FMD) were measured. Heart rate variability and vagal components of autonomic function were determined. Significant reduction of normalized HF power (P < 0.05) and total power (P < 0.01) was observed in T2DM. CIMT and CAC scores were significantly higher while FMD was significantly lower in diabetics (P < 0.01 for all). Median HbA(1c) levels were significantly higher in diabetics. CIMT was inversely and independently associated with total power both in diabetics and controls (P < 0.01 for both groups). There was also an inverse association between total power and median HbA(1c). Autonomic dysfunction, especially parasympathetic neuropathy, was present since early-stage T2DM. This was related to subclinical atherosclerosis. Early detection of cardiac autonomic neuropathy can help us detect the development of atherosclerosis earlier in T2DM to prevent unfavorable outcomes.

A new method for induction of atrioventricular nodal reentrant tachycardia in non-inducible cases.

AIM: In some patients with clinical paroxysmal supraventricular tachycardia (PSVT), who are candidates for radiofrequency (RF) catheter ablation, attempts for the induction of arrhythmia during the electrophysiological study (EPS) fail despite different stimulation protocols even during the isoproterenol infusion and atropine injection. The presence of an atrial-His interval (AH) jump during decremental pre-mature atrial stimulation is the only clue for slow pathway ablation in these patients; in occasional patients, however, the AH jump is an accidental finding and the real arrhythmia is not atrioventricularnodal reentrant tachycardia (AVNRT). We aimed to introduce a new method for the induction of AVNRT in these patients. METHODS AND RESULTS: Ten patients (50% male, mean age=44.40 ± 12.80 years) with clinical PSVT who were referred to our department for the EPS and RF catheter ablation were selected. These patients had documented clinical PSVT with non-inducible arrhythmia during the EPS with different stimulation protocols even during the isoproterenol infusion and atropine injection but they only showed an AH jump. To induce AVNRT, low-watt (15-20), low-temperature (40-45°C) RF currents were delivered into the slow pathway area for a maximum of 40 s. Atrioventricularnodal reentrant tachycardia was inducible in five cases (50%, three male, mean age=45.80 ± 9.65 years). Induction of AVNRT occurred either during the RF current application after the occurrence of junctional ectopic beats or after another stimulation protocol. CONCLUSION: A low-watt, low-temperature RF current application into the slow pathway area can be a provocative method for the induction of AVNRT probably by AV-junction warming and conduction-velocity augmentation.

Sodium bicarbonate plus isotonic saline versus saline for prevention of contrast-induced nephropathy in patients undergoing coronary angiography: a randomized controlled trial.

BACKGROUND: There is controversy about the prophylactic measures proposed for the prevention of contrast-induced nephropathy (CIN). We aim to compare the efficacy of the combination of sodium bicarbonate and isotonic saline and that of isotonic saline alone in preventing CIN. STUDY DESIGN: Randomized double-blind controlled trial. SETTING & PARTICIPANTS: 265 consecutive patients 18 years or older with a serum creatinine level of 1.5 mg/dL or greater undergoing elective coronary angiography from August 2007 to June 2008 in Tehran Heart Center, Tehran, Iran. INTERVENTION: Study participants were randomly assigned to receive either 75 mL of 8.4% sodium bicarbonate added to 1 L of isotonic saline (n = 135) or isotonic saline alone (n = 130) as a bolus of 3 mL/kg for 1 hour before contrast injection, followed by an infusion of 1 mL/kg/h for 6 hours after the procedure. OUTCOMES & MEASUREMENTS: The primary end point was an absolute (>or=0.5 mg/dL) or relative (>or=25%) increase in serum creatinine level 48 hours after the procedure (CIN). RESULTS: There were no significant differences between the bicarbonate and saline groups regarding baseline demographic and biochemical characteristics, including baseline serum creatinine level (1.63 +/- 0.32 [SD] versus 1.66 +/- 0.50 mg/dL), baseline glomerular filtration rate (46.4 +/- 12 versus 45.4 +/- 12 mL/min/1.73 m(2)), and baseline urine pH (5.42 +/- 0.6 versus 5.46 +/- 0.8). Nine patients (7.4%) receiving sodium bicarbonate developed CIN as opposed to 7 patients (5.9%) in the saline group, which was not statistically different (odds ratio, 1.26; 95% confidence interval, 0.45 to 3.50; P = 0.6). LIMITATIONS: The trial did not follow up participants to assess need for dialysis and mortality rate. CONCLUSION: The combination therapy of sodium bicarbonate plus saline does not offer additional benefits over hydration with saline alone in the prevention of CIN.