Crossed my heart, into the gut? A case of cardiac perforation with accompanying diaphragmatic perforation during temporary transvenous pacemaker placement.

Temporary transvenous pacing is generally considered a safe procedure and is commonly performed for various emergent indications. However, complications are quite common with minor complications being more frequent than major life-threatening events. Cardiac perforation is a serious complication associated with the procedure with possible life- threatening consequences. Our report describes the imaging findings in a rare case of cardiac perforation with accompanying diaphragmatic perforation during temporary transvenous pacemaker placement.

A false decrease in the automatically measured atrial pacing threshold when using the automatic pacing threshold adjustment algorithm.

Automatic pacing threshold adjustment algorithms and remote monitoring are widely used to improve the utility of pacemakers and ensure patient safety. However, healthcare providers involved in the management of permanent pacemakers should know the potential pitfalls of these functions. In this report, we present a case of atrial pacing failure induced by the automatic pacing threshold adjustment algorithm that went unnoticed even under remote monitoring.

Rescue left bundle branch area pacing in coronary venous lead failure or nonresponse to biventricular pacing: Results from International LBBAP Collaborative Study Group.

BACKGROUND: Cardiac resynchronization therapy (CRT) using biventricular pacing (BVP) is effective in patients with heart failure, left bundle branch block (LBBB), and reduced left ventricular function. Left bundle branch area pacing (LBBAP) has been reported as an alternative option for CRT. OBJECTIVE: The purpose of this study was to assess the feasibility and outcomes of LBBAP in patients who failed conventional BVP because of coronary venous (CV) lead complications or who were nonresponders to BVP. METHODS: At 16 international centers, LBBAP was attempted in patients with conventional CRT indication who failed BVP because of CV lead complications or lack of therapeutic response to BVP. Heart failure hospitalization (HFH) and death, echocardiographic outcomes, procedural data, pacing parameters, and lead complications including CV lead failure are reported. RESULTS: LBBAP was successfully performed in 200 patients (CV lead failures 156; nonresponders 44) (age 68 ± 11 years; female 35%; LBBB 55%; right ventricular pacing 23%; ischemic cardiomyopathy 28%; nonischemic cardiomyopathy 63%; left ventricular ejection fraction [LVEF] ≤35% in 80%). Procedural duration was 119.5 ± 59.6 minutes, and fluoroscopy duration was 25.7 ± 18.5 minutes. LBBAP threshold and R-wave amplitudes were 0.68 ± 0.35 V @ 0.45 ms and 10.4 ± 5 mV at implant, respectively, and remained stable during mean follow-up of 12 ± 10.1 months. LBBAP resulted in significant QRS narrowing from 170 ± 28 ms to 139 ± 25 ms (P <.001) with V6 R-wave peak times of 85 ± 17 ms. LVEF improved from 29% ± 10% at baseline to 40% ± 12% (P <.001) during follow-up. The risk of death or HFH was lower in those with CV lead failure than in nonresponders (hazard ratio 0.357; 95% confidence interval 0.168-0.756; P = .007) CONCLUSION: LBBAP is a viable alternative to CRT in patients who failed conventional BVP due to CV lead failure or who were nonresponders.

Leadless pacemaker implantation sites confirmed by computed tomography and their parameters and complication rates.

BACKGROUND: Implantations of leadless pacemakers in the septum lower the risk of cardiac perforation. However, the relationship between the implantation site and the success rate, complication rate, and pacemaker parameters are not well-investigated. METHODS: Patients who underwent leadless pacemaker implantation with postprocedural computed tomography (CT) between September 2017 and November 2020 were analyzed. Septum was targeted with fluoroscopic guidance with contrast injection. We divided patients into two groups based on the implantation site confirmed by CT: septal and non-septal, which included the anterior/posterior edge of the septum and free wall. We compared the complication rates and pacemaker parameters between the two groups. RESULTS: A total of 67 patients underwent CT after the procedure; among them, 28 were included in the septal group and 39 were included in the non-septal group. The non-septal group had significantly higher R wave amplitudes (6.5 ± 3.3 vs. 9.7 ± 3.9 mV, p = .001), lower pacing threshold (1.0 ± 0.94 vs. 0.63 ± 0.45 V/0.24 ms, p = .02), and higher pacing impedance (615 ± 114.1 vs. 712.8 ± 181.3 ohms, p = .014) after the procedure compared to the septal group. Cardiac injuries were observed in four patients (one cardiac tamponade, one possible apical hematoma, two asymptomatic pericardial effusion), which were only observed in the non-septal group. CONCLUSIONS: Leadless pacemaker implantation may be technically challenging with substantial number of patients with non-septal implantation when assessed by CT. Septal implantation may have a lower risk of cardiac injury but may lead to inferior pacemaker parameters than non-septal implantation.

Leadless pacemaker through tricuspid bioprosthetic valve: Early experience.

BACKGROUND: Leadless pacemaker (LP) therapy has been proved effective in cases where traditional transvenous right pacing (TRP) failed. TRP through a bioprosthetic tricuspid valve (BTV) has always been considered an unpreferable solution because of possible deleterious effect of permanent pacing leads on BTV function and specifically on tricuspid regurgitation (TR). Very limited data exist about the feasibility and safety of LP implantation in this setting. METHODS: We describe two cases of LP implantation through BTV in patients with failure of epicardial pacemaker implanted after cardiac surgery. The focus is on technical description of the procedure and on electrical and echocardiographic evaluation at implantation and at the follow-up. RESULTS: In both cases, skilled and careful handling of the delivery system as well as proper use of X-ray oblique views was determinant for atraumatic successful valve crossing. Likewise, an accurate selection of the deployment site inside the right ventricle, far enough from the valve to avoid valvular dysfunction, was important for successful implantation. Electrical parameters of LP were satisfying at implantation and at the follow-up. The echocardiogram after implantation and at the follow-up showed no mechanical interference of LP with prosthetic valve, no significant TR, and absence of significant changes in the biventricular function. CONCLUSION: Our data seem to support feasibility and safety of this type of procedure in skilled hands, allowing efficacious pacing without valvular dysfunction or right ventricular (RV) physiology impairment.

Pulmonary hypertensive crisis: A potential reason for right ventricle and pacemaker lead failure.

Cardiac pacemakers have improved patient survival and quality of life, although malfunctions can be seen. We present the case of a girl with Seckel syndrome and congenital complete heart block. She had a single chamber permanent pacemaker in the right ventricle. When she referred us with a pulmonary hypertensive crisis (PHC), it was seen that the device was not pacing even in maximum threshold and pulse width values. After new epicardial lead implantation into the left ventricular apex, capture could be established again. For the cases presenting with capture failure, after eliminating lead-related problems and biochemical abnormalities, PHC should be kept in mind as a reason.

Rate-dependent pacing failure after pacemaker implantation: Novel insights into the mechanism of using adenosine.

An 82-year-old woman received pacemaker implantation for sick sinus syndrome. Two days after the implantation, electrocardiography showed 2:1 atrial pacing failure, followed by a bradycardia-dependent increase in the atrial pacing threshold during a pacemaker examination. However, transient 1:1 atrial pacing capture recovered by adenosine triphosphate (ATP) administration, which was performed to evaluate the bradycardia-dependent pacing failure mechanism. We considered this phenomenon to be caused by Phase 4 depolarization and avoided replacing this atrial lead. Three weeks later, the atrial pacing threshold had improved. We report the potential role of Phase 4 depolarization in a bradycardia-dependent increase in pacing threshold by using ATP.

Delayed ventricular pacing failure and correlations between pacing thresholds, left ventricular ejection fraction, and QTc values in a male with Takotsubo cardiomyopathy.

BACKGROUND: Transient pacing failure caused by transient increased pacing threshold has been reported in patients with transient left ventricular apical dysfunction (Takotsubo cardiomyopathy [TC]). Normal pacing thresholds usually recover after normalization of systolic dysfunction. HYPOTHESIS: Pacing failure correlates with clinics of TC. METHODS: We report the case of a 76-year-old man with a dual chamber pacemaker, admitted for acute chest pain and dyspnea and final diagnosis of TC. One month after index admission, the patient came back complaining again of chest pain. Unexpectedly, admission electrocardiogram showed ventricular pacing failure and an increased pacing threshold. In the following weeks, pacing threshold gradually recovered with left ventricular ejection fraction and QTc values. RESULTS: Ventricular pacing threshold correlated directly to QTc values and inversely to left ventricular ejection fraction over time (P < 0.05). CONCLUSIONS: This is one of the first cases of delayed transient ventricular pacing failure in a male patient with transient left ventricular apical ballooning, in the presence of spared right ventricular function. Given the possibility of acute transient anomalies in myocardial impedance and pacing failure even in the subacute phase of TC several weeks after clinical onset of transient systolic dysfunction, pacing threshold should be carefully monitored in subjects with TC, both during the acute phase of the disease and in first months of follow-up after discharge. Ventricular pacing threshold correlated directly to QTc values and inversely to left ventricular ejection fraction over time.

Pacing failure caused by automatic pacing threshold adjustment system.

Ventricular capture management is an automatic pacing threshold adjustment algorithm that automatically measures pacing threshold through detection of the evoked response after a pacing stimulus. Although it is principally designed to save device battery under the maintenance of the patient׳s safety, we experienced a rare case with serious pacing failure due to a weakness of this algorithm. This pacing failure might be explained by a large variation in the ventricular pacing threshold depending on the atrioventricular interval and daily variation of pacing threshold and concomitant steroid use in this patient.

Sudden failure of ventricular pacing and recovery in a patient with cardiac sarcoidosis.

A 76-year-old woman with sarcoidosis who had an implantable pacemaker for complete atrioventricular block was admitted with syncope. Electrocardiogram revealed ventricular pacing failure, and a marked rise in the ventricular pacing threshold. 18F-Fluorodeoxyglucose positron emission tomography (FDG-PET) indicated increased uptake of FDG in the ventricular septum. Three days after steroid therapy, the ventricular pacing threshold reverted to normal, and FDG-PET showed decreased FDG uptake in the ventricular septum. In this case report, we demonstrate that a sudden deterioration in the ventricular pacing threshold due to worsening cardiac sarcoidosis can be reversed with early steroid therapy.

Performance of Anatomically Designed Quadripolar Left Ventricular Leads: Results from the NAVIGATE X4 Clinical Trial.

INTRODUCTION: The safety and efficacy of a novel family of quadripolar left ventricular (LV) pacing leads designed to pace from nonapical regions of the LV with low pacing capture thresholds was studied in patients undergoing implantation of a cardiac resynchronization therapy defibrillator (CRT-D). METHODS AND RESULTS: Patients receiving a CRT-D were implanted with 1 of 3 ACUITY X4 leads (Spiral Long, Spiral Short, or Straight), designed to address coronary venous anatomical variability. Electrical performance and LV lead related complications were evaluated 3 and 6 months post implantation, respectively. 764 patients (68 ± 11 years, 66% male) were enrolled; 738 (97%) successfully implanted with an ACUITY X4 lead (Spiral L, n = 239, 31%; Spiral S, n = 281, 37%; Straight, n = 218, 29%). A targeted threshold ≤2.5 V was achieved in 644 (94%) patients. The median threshold from the best proximal electrode was lower than the tip electrode (0.9 V [IQR 0.7, 1.3] vs. 1.3 V [IQR 0.7, 2.5], p< 0.001) on Spiral leads. Irrespective of lead implanted, one of the proximal electrodes was the programmed cathode in most patients. The overall LV complication-free rate was 98%. LV lead dislodgment occurred in 8 (1%) patients. PNS occurred in 58 (8%) patients, but only 3 (0.4%) patients required surgical intervention. CONCLUSION: The ACUITY X4 LV leads had low pacing thresholds particularly from proximal electrodes, a high incidence of pacing from the nondistal electrode, and low likelihood of dislodgment or PNS requiring surgical intervention. (ClinicalTrials.gov Identifier: NCT02071173).

A Case of Acute Ventricular Capture Threshold Rise Associated with Flecainide Acetate

Antiarrhythmic agents may increase capture threshold, but this is rarely of clinical significance. Flecainide acetate, a class IC agent, is reported to have a significant effect on the myocardial capture threshold. In this presentation, we report the case of a 72-year-old male, with a previously implanted VVI pacemaker due to sick sinus syndrome, who was treated with flecainide acetate for paroxysmal atrial arrhythmia control. During the fifteenth day of treatment, an abrupt rise in the ventricular capture threshold with ventricular pacing failure was noted. The capture threshold decreased two days after discontinuation of flecainide acetate.