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Leadless cardiac pacemakers such as the Micra™ transcatheter leadless pacing system (Medtronic, Minneapolis, MN, USA) are an alternative to traditional transvenous pacemakers. Implantation of leadless pacemakers, albeit safe, may be associated with complications, including cardiac tamponade; high capture thresholds; and, rarely, ventricular arrhythmias. We report a case of ventricular fibrillation arrest following the implantation of a Micra™ leadless pacemaker.

Left ventricular assist devices (LVADs) provide circulatory support to patients with severe left ventricular systolic dysfunction. Many such patients have a pre-existing implantable cardioverter-defibrillator (ICD) at the time of their LVAD surgery. LVAD implantation can alter the ICD lead parameters, including R-wave sensing, right ventricular capture threshold, and impedance. These changes can in turn affect the ability of the ICD to successfully treat malignant ventricular arrhythmias. In most patients who present with ineffective ICD shocks, the failed shock is assumed to be secondary to the patient's severe cardiomyopathy. Especially, the role of physical examination in such patients is often minimized. In our patient, a thorough history-taking and history-guided physical examination led us to the root cause of the failed ICD shocks. Our patient was noted to have a metal tongue piercing, which was the likely cause of his ineffective ICD shocks. Our case highlights the importance of a comprehensive history-taking and physical examination.

Recently, there have been reports of left ventricular assist device (LVAD) patients presenting with multiple ineffective implantable cardioverter-defibrillator (ICD) shocks. In such patients, the placement of an azygous vein coil by providing an alternative anteroposterior trajectory of the electrical shock vector can enable successful defibrillation. This review discusses a hands-on approach to azygous vein coil implantation. Additionally, we compare our tools and technique to those that have been previously described by other operators. From 2018 to 2021, eight patients were identified who underwent azygous vein coil implantation at MedStar Washington Hospital Center using a specific technique and tools. Demographic and procedural data were obtained by a retrospective review of patient charts, procedure logs, fluoroscopy, and venography performed during coil implantation. The indication for azygous vein coil implantation was ineffective ICD shocks in seven patients. The presenting rhythm was ventricular fibrillation in six (75%) cases and sustained ventricular tachycardia in two (25%) cases. Using the approach described, we were able to successfully implant an azygous vein coil in all eight (100%) patients. There were no procedure-related complications. Postimplantation, defibrillation threshold (DFT) testing was successfully performed in six of eight (75%) patients. One patient failed DFT testing despite placement of an azygous vein coil. In another patient, DFT testing was not performed because the patient was in atrial fibrillation and was not systemically anticoagulated. In conclusion, the placement of an azygous vein coil in LVAD patients with failed ICD shocks using the tools and technique described in this report is safe and highly efficacious (successful in 100% of cases).

Background Coronary sinus (CS) ostial atresia/abnormalities prevent access to the CS from the right atrium (RA) for left ventricular (LV) lead implantation. Some patients with CS ostial abnormalities also have a small persistent left superior vena cava (sPLSVC). Objective The purpose of this study was to describe CS ostial abnormalities and sPLSVC as an opportunity for LV lead implantation and unrecognized source of stroke. Methods Twenty patients with CS ostial abnormalities and sPLSVC were identified. Clinical information, imaging methods, LV lead implantation techniques, and complications were summarized. Results Forty percent had at least 1 previously unsuccessful LV lead placement. In 70%, sPLSVC was identified by catheter manipulation and contrast injection in the left brachiocephalic vein, and in 30% by levophase CS venography. In 30%, sPLSVC was associated with drainage from the CS into the left atrium (LA). When associated with CS ostial abnormalities, the sPLSVC diameter averaged 5.6 ± 3 mm. sPLSVC was used for successful LV lead implantation in 90% of cases. In 80%, the LV lead was implanted down sPLSVC, and in 20%, sPLSVC was used to access the CS from the RA. Presumably because of unrecognized drainage from the CS to the LA, 1 patient had a stroke during implantation via sPLSVC. Conclusion When CS ostial abnormalities prevent access to the CS from the RA, sPLSVC can be used to successfully implant LV leads. In some, the CS partially drains into the LA and stroke can occur spontaneously or during lead intervention. It is important to distinguish sPLSVC associated with CS ostial abnormalities from isolated PLSVC.

Background Placement of a left ventricular assist device (LVAD) has been described to compromise implantable cardioverter-defibrillator (ICD) defibrillation threshold (DFT). Elevated DFT will have negative consequences and increases the risk of ineffective ICD shocks, morbidity, and mortality. DFT testing is not routinely performed in clinical practice, despite this fact. Objective We describe the clinical characteristics of 7 LVAD patients who presented with multiple ineffective ICD shocks, along with the management strategy in such patients. Methods Seven patients (5 male, mean age 52.2 ± 9 years, 85.7% nonischemic cardiomyopathy) with an ICD in situ who progressed to NYHA class IV, ACC/AHA stage D chronic systolic congestive heart failure who underwent successful LVAD implantation presented to our institution in the setting of ventricular tachyarrhythmia and ineffective ICD shocks. Six patients underwent implantation of azygos and subclavian coils with subsequent DFT testing. The remaining patient was made comfort care. Results Five patients had successful DFT testing with azygos (n = 4) and subclavian (n = 1) defibrillation coil implantation. One patient had unsuccessful DFT testing despite evaluation of multiple shock vectors. There were no major or minor vascular complications in any of the cases. There were no procedural-related deaths. Conclusion This case series highlights the need for a systematic approach to management of ICDs and DFT testing in LVAD patients. The addition of new shock vectors with azygos and subclavian coil implantation may reduce DFT, shock burden, morbidity, and mortality.

New-onset left bundle branch block (NLBBB) is the most common complication after transcatheter aortic valve implantation (TAVI). Expert consensus recommends temporary transvenous pacemaker (TTVP) support for 24 hours in these patients. To date, no study has examined TTVP use during the index hospitalization in detail. Therefore, we aimed to assess TTVP use in patients with TAVI who developed NLBBB. In this prospective observational study, we performed a detailed analysis of 24-hour telemetry in patients who developed NLBBB during TAVI. Baseline characteristics and procedural and postprocedural data were recorded. The primary outcome was pacing by the TTVP. We evaluated inappropriate TTVP use, electrophysiology study findings, permanent pacemaker (PPM) implantation, and NLBBB resolution. A total of 83 patients (74.4 ± 8.7 years, 41% female) developed NLBBB during TAVI. During index hospitalization, 1 patient (1%) required TTVP because of complete heart block and received a PPM. Five of the 83 (6%) patients were inappropriately paced, and 1 patient (1%) had ventricular fibrillation, likely secondary to TTVP. A total of 34 patients (41%) underwent electrophysiology study during hospitalization, with 4 of 83 (5%) subsequently receiving a PPM. One (1%) patient died during hospitalization, and 9 patients were lost to follow-up because of the COVID-19 pandemic. Of the remaining 73 patients with a 30-day follow-up, NLBBB had resolved in 36 (49%) at 30 days, and 2 (3%) were readmitted with complete heart block and received PPM. In conclusion, in patients with TAVI who develop NLBBB, temporary pacing is rarely necessary, may carry additional risks to the patient, and prolong hospitalization time.

Background Patients with wire and catheter refractory venous occlusion are traditionally referred for pectoral transvenous lead extraction (TLE) to obtain venous access. TLE causes 1-2-mm circumferential mechanical or laser destruction of tissue surrounding the lead(s). This not only exposes the patient to the risk of major complications but also can damage non-targeted leads. We present a series of patients where retained wire femoral lead removal and fibroplasty was used to obtain venous access in patients with refractory obstruction. Methods Between 2008 to 2021, we identified 17 patients where retained wire lead removal followed by fibroplasty was used to retain venous access. Demographic and procedural data were obtained by retrospective review of patient charts. Results We were able to successfully obtain venous access in all 17 patients in whom this technique was attempted. In 2 patients the target lead was ≤ 1 year old. In the remaining 15 patients, the average dwell time of the target lead(s) was 6 years. There were no procedure-related complications, and no changes in the parameters of other leads were noted. Conclusion Retained wire femoral lead removal and fibroplasty is safe and highly efficacious at obtaining venous access in patients with refractory venous occlusion. If the target lead(s) is ≤ 1 year old, this technique can help obtain venous access at the time of the initial surgery, hence avoiding the need for TLE. Furthermore, in patients referred for TLE to obtain venous access, this technique by avoiding the use of TLE tools spares the patient of the associated risks. This article is protected by copyright. All rights reserved.

Takotsubo cardiomyopathy (TCM) is a recently emerging syndrome characterized by transient left ventricular wall motion abnormalities unexplained by obstructive coronary artery disease (CAD).1 Emotional or physical stress is usually illustrated in most cases, with catecholamine excess often playing a mechanistic role.1 We present a case of TCM induced by an unusual trigger: elective direct current (DC) cardioversion for atrial flutter (AF).

Leadless cardiac pacemakers such as the Micra transcatheter leadless pacing system provide an alternative to traditional transvenous pacemakers. Implantation of leadless pacemakers, albeit safe may be associated with complications including cardiac tamponade, high capture thresholds, and rarely, ventricular arrhythmias. We report a case of ventricular fibrillation arrest following Micra leadless pacemaker implantation.

Subclavian venous obstruction is a common complication after cardiac device placement. Patients typically remain asymptomatic but at times may present with acute symptoms due to thrombus formation immediately after device placement or years later, due to chronic obstruction, with pain and swelling. Various techniques have been attempted to resolve symptoms in patients with chronic lead-related subclavian obstruction but are associated with a high recurrence of restenosis. Drug coated balloons (DCB) have been used subsequently after pre-dilation with high-pressure balloons, of the stenosed region, in patients with arteriovenous fistula obstruction, and have shown promising results. We discuss the utilization of DCB in our patient with chronic subclavian obstruction due to a permanent pacemaker lead.

Brugada phenocopies are interesting clinical entities with electrocardiographic (ECG) patterns indistinguishable from the inherited Brugada syndrome. In patients with Brugada phenocopies, these ECG patterns are expected to resolve with resolution of the underlying condition.

Cardiac device infections (CDIs) represent a serious complication after the implantation of pacemakers and defibrillators. In addition to antimicrobials, complete hardware removal, mostly with percutaneous lead extraction (PLE), is necessary to limit recurrences. However, CDI diagnosis is often difficult and is sometimes delayed, and scarce data exist on how the timing of PLE may affect clinical outcomes. In this study, the in-hospital outcomes of 52 consecutive patients with CDIs who underwent PLE were retrospectively analyze. Co-morbidities such as diabetes mellitus, congestive heart failure, renal insufficiency, and end-stage renal disease were highly prevalent in the study cohort. Patients were divided into group A (bacteremia or device endocarditis) and group B (localized pocket infection). In-hospital mortality was 29% in group A and 5% in group B (p = 0.02) and was due mostly to sepsis. Hospital stays were shorter in group B patients (5.7 vs 21.7 days, p0.001). Presentation with hypotension was more commonly observed in group A patients and was associated with higher in-hospital mortality, whereas pocket findings correlated with better survival. Postoperative courses after PLE were uneventful in most patients, and no fatal complications were observed. PLE was performed significantly earlier in group B patients (hospitalization day 1.3 vs 7.6, p0.001). PLE performed within 3 hospitalization days was associated with lower in-hospital mortality (p = 0.01). In conclusion, PLE performed within 3 days from admission is associated with shorter hospitalization and better survival. A timely diagnosis is crucial, particularly in the absence of local findings, because early treatment with PLE is likely to prevent the catastrophic outcomes of unrelenting CDIs.

Polymorphic ventricular tachycardia (PVT) is a form of ventricular tachycardia characterized by QRS complexes that seem to change direction during the tachycardia. If associated with a prolonged QT interval, it is called torsades de pointes. In the absence of a congenital long QT syndrome, torsades is seen with certain drugs such as antiarrhythmic agents (Class IA, IC, III), psychotropic medications, antidepressants, antihistamines, and electrolyte disturbances. We report the first case of polymorphic ventricular tachycardia with normal QT interval associated with the oral use of levofloxacin in the absence of other etiologies known to cause these arrhythmias.

It was hypothesized that a wall motion score (WMS) ofor=16% determined by chordal analysis (WMS=% of chords analyzed with normal or hyperkinetic motion) from a right anterior oblique (RAO) left ventriculogram would be a predictor for perioperative (30-day or in-hospital) or long-term mortality in patients from the CABG-Patch Trial.One hundred and eighty-nine patients from the trial with a LVEF ofor=36% were retrospectively studied. Patients were divided into two groups according to a WMS ofor=16% (n=81) or16% (n=108), respectively, calculated from a preoperative RAO ventriculogram. There was no difference in EF between the two groups (26.5+/-5.5 vs. 27.8+/-5.3%, respectively). Eight (9.9%) versus three (2.8%) patients died perioperatively in the low versus the high WMS group, respectively. The relative risk for perioperative death in the low WMS group was 3.6 (P0.04). Kaplan-Meier estimates of cumulative survival did not reveal any statistical difference between the two groups over 4 years (P=0.11). Subgroup analysis revealed that patients with a WMS ofor=16% had a better survival when treated with an ICD at the time of surgery compared to those not treated with an ICD (P=0.046).These data indicate that poor LV function, as assessed by a WMS ofor=16%, can identify a subgroup of low EF patients who are at increased risk for perioperative mortality after bypass surgery. Conversely, long-term estimates of survival in patients with WMSor=16 and16% were not significantly different, although subgroup analysis revealed that patients with a WMSor=16% may benefit from implantation of an ICD at the time of surgery.

The use of MAP recording techniques has been said to have bridged the gap between basic in vitro investigation of the transmembrane action potential and observations made in situ from the beating heart. With regard to antiarrhythmic agents, MAP recordings are particularly useful in evaluating drugs which prolong repolarization. The simultaneous measurement of MAP and ERP at the same site permits the comparison of drug effects on repolarization and refractoriness. The ability to safely and reliably record the MAP contributes importantly to the evaluation and classification of antiarrhythmic drug effects in vivo and may ultimately lead to more rational selection of drug therapy for individual patients. Antiarrhythmic drug effects demonstrated with MAP recordings have generally shown good agreement with the Vaughan Williams classification of electrophysiological actions. An important key to drug efficacy may be that some drugs prolong refractoriness beyond their effect on repolarization. Conversely, a potential explanation for proarrhythmia may lie in slowing of conduction without the concomitant protective effect of postrepolarization refractoriness. The phenomenon of use dependence, which has been demonstrated for many drugs, suggests why an agent that prevents induction of arrhythmia during programmed stimulation in the electrophysiology laboratory may not prevent spontaneous arrhythmia initiation at slower heart rates. The paramount task of clinical electrophysiology is the successful treatment of rhythm disturbances. The more detailed and quantitative evaluation of drug effects afforded by MAP recordings may ultimately result in the more effective use of antiarrhythmic drugs in general and to more precise tailoring of therapy for individual patients.

The evaluation of survivors of sudden cardiac death with serial electrophysiologic studies involves a lengthy and expensive hospitalization, especially when an automatic implantable cardioverter-defibrillator is ultimately necessary. The cost efficacy of this conventional approach was therefore compared with direct implantation of a cardioverter-defibrillator after the first electrophysiologic study. Thirty-two survivors of sudden death who had inducible ventricular tachycardia during their initial electrophysiologic study underwent serial drug trials. At discharge 12 (37%) were taking an antiarrhythmic drug found to prevent induction of ventricular tachycardia and 20 underwent cardioverter-defibrillator implantation after serial drug trials proved ineffective. The average length of hospitalization for this group that had undergone serial drug testing was 20.2 +/- 9.3 days at an average cost of $48,900 +/- $31,600. Seven survivors of sudden death had no inducible ventricular tachycardia during their initial electrophysiologic study and underwent direct cardioverter-defibrillator implantation. Their average length of hospitalization was 12.6 +/- 6.2 days at an average cost of $40,400 +/- $8,300. It is concluded that automatic implantable cardioverter-defibrillator implantation as an early intervention is not more costly and indeed may be cost-effective compared with therapy guided by serial electrophysiologic testing. As antitachycardia devices become more versatile, long lived and easier to implant, earlier implantation is likely to compare even more favorably with drug therapy.

The “pacemaker syndrome” refers to a wide variety of clinical presentations of intolerance to ventricular pacing ranging from mild light-headedness to frank syncope. 1 These problems are thought to result from the loss of atrioventricular synchrony with consequent loss of the atrial contribution to left ventricular filling, and, in some cases, intact ventriculoatrial conduction with inappropriate atrial-ventricular systole, increased systemic and pulmonary venous pressure and consequent reflex drop in systemic arterial pressure. 2 Some studies have suggested that it is the loss of chronotropic response during VVI pacing that leads to symptoms in many patients; this response can be improved by activity-responsive VVI pacing. 3 We report a case of pacemaker syndrome that resulted from the use of an activity-responsive VVI pacing system.

S T-segment elevation persists in 60% of patients after healing of an anterior wall acute myocardial infarction.’ Its traditional association with left ventricular aneurysm has been difficult to establish.1%2 ST elevation is not consistently related to the degree of left ventricular dysfunction present after healing of an anterior wall infarction.2 An association with dyskinetic wall motion has been suggested,3 but a link between the contraction abnormality and the electrocardiographic finding has not been elucidated. Thus, it is reasonable to consider an electrophysiologic basis for persistent ST elevation. We investigated the possibility that clinical electrophysiologic testing might demonstrate a distinguishing characteristic of patients with this finding. The standard 12-lead electrocardiograms of 490 of the 495patients who underwent electrophysiologic study in the arrhythmia center of the Washington Hospital Center between July 1,1985, and August 31,1988, were available for review. Predetermined criteria for anterior wall myocardial infarction (Table I) were identified in 49. Excluded were 2 patients in whom programmed ventricular stimulation was not part of the study, 5 who had no clinical history of an acute myocardial infarction and 6 whose infarction had occurred within 2 weeks of the electrophysiologic study. The infarction had occurred >I year previously in 20 (56%) of the 36patients whose electrocardiograms were included in the study. Each electrocardiogram was reexamined by 2 of the investigators for the presence of ST elevation in the leads reflecting the acute infarction. Any elevation above the TP interval at the midpoint of the ST’ was carefully measured by each. The mean of the 2 measurements was used to classify patients with regard to the magnitude of the ST elevation. ST elevation was deemed present when >I mm.] ST-elevation was considered very elevated when >2 mm. Agreement in the measurement of ST between the 2 readers was good. In only 6 instances did the measurements vary by >0.5 and in only 2 did they vary by >l mm. Only in the latter 2 patients was the classification potentially affected, and these 2 electrocardiograms were reviewed by the readers and a consensus was reached. During the electrophysiologic study 13 patients were free of antiarrhythmic agents, but the clinical situation dictated continuation of drug therapy in 23. The technique used has been previously described.4 If sustained

We surveyed 12 medical centers with regard to the reuse of pacing catheters during electrophysiologic studies. The prevalence of superficial skin infections or bacteremia related to EP studies was extremely low, and was not significantly different in the catheter reuse group compared to the single use group. We conclude that catheter resterilization and reuse is safe and cost-effective.