Extraction of a 6-year-old leadless pacemaker (MICRA transcatheter pacing system) using commercially available removal tools: A case report.

INTRODUCTION: Leadless pacemakers are associated with a low risk of infection, so indications for their removal are rare. One can expect that the dwell time of the device correlates with a more difficult removal, but it has not been proved so far. METHODS AND RESULTS: We present a case of a patient in whom MICRA transcatheter pacing system was successfully removed with nondedicated commercially available tools, 70 months after implantation. CONCLUSION: A successful removal of the MICRA leadless pacemaker is possible, and may be safe even many years after the device implantation, despite a lack of dedicated tools. Due to the potential risk of complications, the benefits and risks of the procedure should be weighted before making a final decision.

Early Smartphone App-Based Remote Diagnosis of Silent Atrial Fibrillation and Ventricular Fibrillation in a Patient with Cardiac Resynchronization Therapy Defibrillator.

Due to distressing statistics concerning cardiovascular diseases, remote monitoring of cardiac implantable electronic devices (CIED) has received a priority recommendation in daily patient care. However, most bedside systems available so far are not optimal due to limited patient adherence. We report that smartphone app technology communicating with CIED improved the patient's engagement and adherence, as well as the accuracy of atrial and ventricular arrhythmias diagnosis, thus offering more efficient treatment and, consequently, better patient clinical outcomes. Our findings are in concordance with previously published results for implantable loop recorders and pacemakers, and provide new insight for heart failure patients with an implanted cardiac resynchronization therapy defibrillator.

Recall devices: Defects at initial visit and during remote monitoring supported follow-up.

BACKGROUND: In March 2021, Biotronik informed about the risk of premature battery depletion in a group of implantable cardioverter-defibrillators. Following the manufacturers' recommendation, our center executed a recall and introduced remote monitoring (RM) in patients with susceptible devices. This study reports the rate of premature battery depletion in our center and events found in RM-supported follow-up. METHODS: Single-center observational study. RESULTS: Out of the 206 susceptible implanted devices, 125 patients appeared for the visit and RM was introduced in 107 (83%) patients. Until the visit, three (2.4%) devices required replacement due to battery depletion, and a further three (2.4%) devices had unexpected battery depletion during follow-up. CONCLUSIONS: The recalled devices had a higher rate of battery exhaustion than expected, while other device or lead defects were less common.

Complications of cardiac resynchronization therapy implantation: De novo implants versus upgrades.

BACKGROUND: Cardiac resynchronization therapy (CRT) is a well-established treatment of patients with advanced heart failure and electrical dyssynchrony. Implantation of those devices is in some cases associated with intervention on a formerly implanted system. The aim of this analysis was to compare the rate and type of complications of de novo implants and upgrades to CRT-D. METHODS: Retrospective data were collected from medical records, including 326 patients treated with CRT-D between 2015 and 2020. The following data were analyzed: procedure data including complications, demographics, co-morbidities, pharmacotherapy, and laboratory tests. The primary endpoint of the study was all-cause mortality. RESULTS: A total of 326 procedure were included, of which 53% (n = 172) were de novo implants and 47% (n = 154) were upgrades. The groups did not differ in the incidence of complications: in the de novo group: 25.5% (n = 44); in the upgrade group: 30.5% (n = 47), p = 0.78. The incidence of complications was also similar in respect of the following: early (p = 0.98) and late (p = 0.45), infectious (p = 0.38) and non-infectious (p = 0.82), surgical (p = 0.38) and device or lead related (p = 0.6). The most common complication in the upgrade group was pocket hematoma (n = 9, 5.8%) and in the de novo group pneumothorax (n = 8, 4.7%). CONCLUSIONS: Upgrade procedures of are not associated with a higher percentage of complications than de novo implantations of CRT-D. Previously implanted cardiac implantable electronic device should not limit the implantation of CRT-Ds.

Follow-up and characteristics of recipients of cardiac resynchronization therapy with and without a defibrillator.

BACKGROUND: Cardiac resynchronization therapy defibrillator (CRT-D) and pacemaker (CRT-P) are treatment options for patients with advanced heart failure and electrical dyssynchrony. Current guidelines provide only factors favoring, not specific recommendations as to implant CRT-D or CRT-P. This analysis aimed to compare and contrast populations of CRT-D and CRT-P recipients. METHODS: Retrospective data were collected from medical records, including 231 patients treated with either CRT-D or CRT-P between 2015 and 2019. Following data were analyzed demographics, co-morbidities, pharmacotherapy, laboratory tests, and data related to the procedure of implantation. The primary endpoint of the study was all-cause mortality. RESULTS: A total of 231 patients were included (mean age [standard deviation, SD], 64.1 [12.3] years, 76% male), of these, 13.6% (n = 32) with CRT-P and 86.4% (n = 199) with CRT-D. Mean New York Heart Association (NYHA) class did not differ between the groups: 2.23 (0.9) in CRT-P and 2.35 (0.6) in CRT-D group (P = 0.42). Mean left ventricular ejection fraction was lower in patients eligible for CRT-D: 27.1% vs. 38% (P < 0.001). Patients were followed for a median (interquartile range [IQR]) of 29 (13-44) months and survival in the CRT-P group was 84%, in CRT-D - 82% (P = 0.74). Patients in the CRT-P group were older, and more often after atrioventricular node ablation. The CRT-P group had tendency towards higher Charlton Comorbidity Index, reaching a mean of 4.66 (1.5) points vs. 3.96 (1.5) points in CRT-D (P = 0.06). CONCLUSIONS: Populations with CRT-P and CRT-D differ in terms of comorbidities; however, they have similar survival. Further studies are required to identify a group of patients, who derive a benefit from adding a defibrillator.

Shortening baroreflex delay in hypertrophic cardiomyopathy patients -- an unknown effect of ß-blockers.

AIMS: Hypertrophic cardiomyopathy (HCM) is characterized by left ventricular hypertrophy and impaired diastolic and systolic function. Abnormal sympathetic-parasympathetic balance is a potential stimulus for left ventricular hypertrophy in HCM patients. ß-Blockers are routinely used in HCM for their strong negative inotropic effect; however, these drugs also influence the sympathetic-parasympathetic balance. This study aimed to determine the autonomic control of the cardiovascular system and the autonomic effects of ß-blockers in HCM patients treated or untreated with ß-blockers. METHODS: Among 51 HCM outpatients (18-70 years old; 29 men) there were 19 individuals with no medication and 32 subjects treated with a ß-blocker. Fourteen age- and gender-matched (23-70 years old; nine men) healthy volunteers were enrolled in the control group. Continuous, non-invasive finger blood pressure was recorded during supine rest for 30 min. Autonomic regulation of the cardiovascular system was measured by heart rate variability and spontaneous baroreflex function (cross-correlation sequence method). RESULTS: The mean pulse interval, time domain and spectral measures of heart rate variability and baroreflex sensitivity were comparable between HCM patients, treated or not with ß-blockers, and the control group. However, the delay of the baroreflex was significantly longer in HCM patients who were not treated with ß-blockers [2.0 (1.6-2.3) s] in comparison with HCM patients receiving ß-blockers [1.4 (1.1-1.8) s; P = 0.0072] or control subjects [1.2 (0.8-1.8) s; P = 0.0025]. This delay did not differ between HCM patients treated with ß-blockers and the control group. CONCLUSIONS: Hypertrophic cardiomyopathy not treated with ß-blockers is accompanied by prolonged baroreflex delay. The use of ß-blockers normalizes this delay.

Exercise capacity, arrhythmic risk profile, and pulmonary function is not influenced by intracoronary injection of bone marrow stem cells in patients with acute myocardial infarction.

OBJECTIVES: To evaluate influence of Bone Marrow Stem Cells (BMSC) intracoronary infusion on exercise capacity, pulmonary function, heart rate recovery and SAECG in patients with AMI of anterior wall, compared to control group--from baseline in the acute phase during 12 months follow up. METHODS: Forty five patients were randomized 2:1 to BMSC group (n = 31 pts) or to control group (n = 14 pts). BMSC were administered into infarct related artery (IRA) at 4-6 day after primary PCI. Patients were followed up with cardiopulmonary exercise testing. The QRS duration, QT and QTc interval were measured and signal averaged ECGs (SAECG) were performed to evaluate late potentials. RESULTS: There were no significant differences between both groups neither at peak VO(2) (190.7 ± 7.4 at baseline; 24.2 ± 5.2 at 6 months; 22.2 ± 7.4 ml/kg/min at 12 months vs 18.4 ± 8.2 at baseline; 22.0 ± 7.2 at 6 months; 21.8 ± 6.2 ml/kg/min at 12 months; BMSC vs control group respectively; p = ns), nor VO(2) at anaerobic threshold, nor in VE/VCO(2) slope, RER, and systolic blood pressure at peak exercise at baseline and any time point of follow-up. There were no significant differences between groups concerning HR peak, HRR1 and HRR2 at any time point and also QRS, QT parameters, and SAEKG. There were no significant differences between both groups at any time point (baseline, 6 and 12 months) concerning FVC, FEV(1) and FVC/FEV(1) and % of their normal values. CONCLUSIONS: We did not find that BMSC therapy in patients with anterior wall myocardial infarction influences exercise capacity. We did not confirm it's potential proarrhythmogenic influence as assessed with SAECG and standard ECG analysis.

Parameters of arterial function and structure in adult patients after coarctation repair.

Regardless of a successful operation, patients with coarctation of aorta (CoAo) are exposed to the risk of hypertension and a propensity to vascular and end-organ damage. The aim of this study is to evaluate the influence of residual aorta stenosis as well as the age at the operation on the parameters of arterial function and structure in patients after CoAo repair. Eighty-five patients after CoAo repair (53 males; mean age: 34.6 ± 10.3 years, mean age at the repair: 10.9 ± 8.2 years) were enrolled in the study. The control group consisted of 30 healthy subjects (18 males; mean age: 33.6 ± 8.2 years). Indices of systemic arterial remodeling [flow-mediated dilatation (FMD), nitroglycerine-mediated vasodilatation (NMD), carotid intima-media thickness (IMT), pulse wave velocity (PWV)] were analyzed in all study patients. In normotensive patients after CoAo repair (47/55%), a significantly increased PWV was observed in comparison to the control group (6.8 ± 1.2 vs. 5.4 ± 0.9 m/s; p = 0.003), with no difference in IMT values (0.53 ± 0.1 vs. 0.51 ± 0.1 mm; p = 0.06). Mean FMD (4.8 ± 2.8 vs. 8.5 ± 2.3%; p = 0.00003) and NMD (11.3 ± 4.6 vs. 19.8 ± 7.2%; p = 0.00001) were lower than in the controls. In patients with a residual aorta stenosis (46/54%), defined as an arm-leg pressure gradient ≥ 20 mmHg, no differences were found within the scope of both systolic and diastolic blood pressure and of all of the examined vascular parameters. No significant correlations were revealed between the vascular parameters and the gradient across descending aorta as well as the age at the operation. Residual stenosis in the descending aorta does not affect the arterial vasodilatation nor stiffness in patients after CoAo repair. An early surgery does not influence the remodeling of the vessels, which supports the thesis that CoAo is a generalized vascular disease and that even an early operation cannot prevent the progressive and vascular changes and end-organ damage.