Extremally rare cause of AV block during typical atrial flutter ablation not related to conduction tissue injury.

BACKGROUND: 51-year-old female with extensive prior atrial surgery involving myxoma resection and patch septum repair and prior typical atrial flutter as well as peripatch reentry underwent redo radiofrequency ablation of typical atrial flutter. METHODS: After high density mapping was performed, and gap in the prior typical flutter line was ablated. RESULT: During the ablation transient atrioventricular (AV) block was noted. Subsequent remapping of the right atrium revealed that there was a narrow strip of tissue between the cavo-tricuspid isthmus (CTI) and the coronary sinus (CS) os on which activation of the AV node was now depending. From all other directions, the AV node was surrounded by scar tissue. CONCLUSIONS: The most likely explanation for the transient AV block during the ablation procedure is that there was reversible injury to the tissue strip between the CTI and the CS os, which is critical for the activation of the AV node.

Sleep Apnea as a Risk Factor for Diastolic Dysfunction: A Systematic Review and Meta-Analysis.

BACKGROUND: This meta-analysis assessed the relationship between obstructive sleep apnea (OSA) and echocardiographic parameters of diastolic dysfunction (DD), which are used in the assessment of heart failure with preserved ejection fraction. METHODS: We searched the databases including Ovid MEDLINE, Ovid Embase, Scopus, Web of Science, Google Scholar, and EBSCO CINAHL from inception up to December 26, 2020. The search was not restricted to time, publication status, or language. Two independent investigators screened the identified studies and extracted the data in duplicate. We conducted a meta-analysis using RevMan v.5. The risk of bias was assessed using Cochrane collaboration tools. Comparisons were made between patients with OSA, diagnosed in-laboratory polysomnography or home sleep apnea testing, and patients without OSA in relation to established markers of DD. RESULTS: Primary search identified 2,512 studies. A total of 18 studies including 2,509 participants were included. The two groups were free of conventional cardiovascular risk factors. Significant structural changes were observed between the two groups. Patients with OSA exhibited greater left atrial volume index (LAVI) (3.94 95% CI [0.8, 7.07]; p = 0.000) and left ventricular mass index (11.10 95% CI [2.56, 19.65]; p = 0.000) as compared to control group. The presence of OSA was also associated with more prolonged deceleration time (10.44 ms 95% CI [0.71, 20.16]; p = 0.04), isovolumic relaxation time (IVRT) (7.85 ms 95% CI [4.48, 11.22]; p = 0.000), and a lower ratio of early to late mitral inflow velocities (E/A) ratio (-0.62 95% CI [-1, -0.24]; p = 0.001) suggestive of early DD. The early mitral inflow velocity to mitral annular early diastolic velocity (E/e') ratio (0.94 95% CI [0.44, 1.45]; p = 0.000) was increased. Linear correlation between severity of OSA and LAVI and IVRT parameters was observed but this association did not sustain for the E/A and E/e'. The ejection fraction was not significantly different between patients with OSA and healthy controls (-0.48 95% CI [-1.18, 0.23]; p = 0.18). CONCLUSION: An association between OSA and echocardiographic parameters of DD was detected that was independent of conventional cardiovascular risk factors. OSA may be independently associated with DD perhaps due to higher LV mass. Investigating the role of continuous positive airway pressure therapy in reversing or ameliorating DD is recommended.

Treatment of Sleep Apnea with Positive Airway Pressure and Its Association with Diastolic Dysfunction: A Systematic Review and Meta-Analysis.

BACKGROUND: This meta-analysis assessed the effect of long-term (>6 weeks) noninvasive positive airway pressure (PAP) on diastolic function in patients with obstructive sleep apnea (OSA). METHODS: We searched the databases for randomized clinical trials including Ovid MEDLINE, Ovid Embase Scopus, Web of Science, Google Scholar, and EBSCO CINAHL from inception up to December 20, 2019. The search was not restricted to time, publication status, or language. Two independent investigators screened the studies and extracted the data, in duplicate. Risk of bias was assessed using Cochrane collaboration tools. RESULTS: A total of 2,753 abstracts were resulted from literature search. A total of 9 randomized clinical trials assessing the effect of long-term (>6 weeks) PAP on diastolic function in patients with OSA including 833 participants were included. The following echo parameters were found in treated patients: a decrease in deceleration time (-39.49 ms CI [-57.24, -21.74]; p = 0.000), isovolumic relaxation time (-9.32 ms CI [-17.08, -1.57]; p = 0.02), and the ratio of early mitral inflow velocity to mitral annular early diastolic velocity (-1.38 CI [-2.6, -0.16]; p = 0.03). However, changes in left-atrial volume index and the ratio of early to late mitral inflow velocities were not statistically different. The risk of bias was mild to moderate among the studies. CONCLUSION: Our results suggest that chronic treatment of moderate to severe OSA with noninvasive PAP is associated with improvement in echocardiographic findings of diastolic dysfunction.

Frequency of Complete Atrioventricular Block Complicating ST-Elevation Myocardial Infarction in Patients Undergoing Primary Percutaneous Coronary Intervention.

OBJECTIVES: ST-segment elevation myocardial infarction (STEMI) can be associated with many conduction disturbances including complete atrioventricular block (CAVB). CAVB complicating STEMI resulted in an increased mortality before the modern era of primary percutaneous coronary intervention (PCI). The aim of this study was to ascertain the rate and risk factors for CAVB in STEMI patients undergoing rapid reperfusion with PCI. METHODS: We analyzed 223 patients presenting with STEMI. Patient characteristics, procedural characteristics, and in-hospital data were compared between patients with and without CAVB. RESULTS: Out of 223 patients, 174 underwent PCI; the majority (87%) was African-American. CAVB was present in 8 patients (4.6%), and 6 of them had RCA occlusion. Independent predictors of CAVB included diabetes mellitus, female gender, lower systolic and diastolic blood pressure, and inferior-lateral/lateral STEMI. Ten patients (5.7%) required temporary pacing at presentation; only 1 patient required permanent pacing before discharge. No patient with anterior STEMI developed CAVB. CONCLUSIONS: The incidence and in-hospital mortality rate of CAVB in patients with STEMI who underwent primary PCI was reduced when compared to data from the thrombolytic era. This may be due to faster flow recovery in the infarct-related artery achieved with PCI.

Early Hemodynamic Changes during Head-Up Tilt Table Testing Can Predict a Neurocardiogenic Response in an African-American Patient Population.

BACKGROUND: Head-up tilt table testing (HUTT) is time-consuming and associated with increased patient morbidity. Hemodynamic changes that occur during the early phase of HUTT may be predictive of neurocardiogenic syncope. METHODS: A retrospective chart review was performed in 119 consecutive African Americans ( 57 ± 19) who underwent HUTT for evaluation of syncope of unknown etiology. Positive responses were defined as the development of symptoms linked with a systolic blood pressure (BP) <90 mm Hg, heart rate <50 b.p.m. or sinus arrest >3 s. Hemodynamic variables during the passive phase of HUTT were analyzed and results were then classified as a function of various predictors. RESULTS: Sixty-two subjects (52%) had positive HUTT, and 57 (48%) had negative HUTT. Early changes in BP variables from baseline significantly predicted HUTT responses (p < 0.05). There was also a significant interaction between age and BP. An algorithm based on age and BP was developed which had positive and negative predictive values of 67.7 and 93%, respectively, with an accuracy of 79.8%. CONCLUSION: A novel algorithm utilizing the patients' age and changes in both systolic and diastolic BP during the early phase of HUTT enables the prediction of HUTT results without the use of vasoactive stimulation, allowing for rapid diagnosis, decreased patient morbidity and reduction in costs.

Simplified automated right ventricular overdrive pacing for rapid diagnosis of supraventricular tachycardia.

OBJECTIVES: The purpose of this study was to prospectively evaluate the feasibility and diagnostic value of right ventricular overdrive pacing (RVOP) during supraventricular tachycardia (SVT) using a 2-catheter approach with automatic pacing from the right ventricular inflow (RVIT) and outflow tract (RVOT). METHODS: One hundred and thirty-six consecutive patients (with 138 arrhythmias, mean age 36 ± 20 years, range 4-95) were enrolled in this study. Only coronary sinus and ablation catheters were used. RVOP was delivered from RVIT and then from RVOT. Each attempt consisted of 10 synchronized beats delivered at a cycle length of 10-40 ms longer than the tachycardia cycle length. RESULTS: RVOP was sufficient to confirm the transition zone within the first 9 beats in the majority of SVTs. Atrial perturbation (acceleration, delayed) in the transition zone was detected in all patients with orthodromic atrioventricular (AV) reentry. Patients with typical AV nodal reentry, atypical AV nodal reentry and atrial tachycardia did not show atrial timing perturbation during fusion complexes of RVOP. CONCLUSIONS: Synchronized RVOP from RVIT or RVOT is an easy and accurate method for the quick and reliable differential diagnosis of SVT in various clinical settings, particularly when only a limited number of catheters are used.

Influence of atrioventricular optimization on hemodynamic parameters and quality of life in patients with dual chamber pacemaker with ventricular lead in right ventricular outflow tract.

BACKGROUND: The aim of this study was to ascertain whether individual atrioventricular delay (AVD) optimization using impedance cardiography (ICG) offers beneficial hemodynamic effects as well as improved exercise tolerance and quality of life in patients with requiring constant right ventricular pacing. METHODS: There were 37 patients with advanced AV block included in the study. Several examinations were performed at the beginning. Next, the optimization of AVD by ICG was done. The next step of the study patients have been randomized into optimal AVD group (AVDopt) or factory setting group (AVDfab). After 3 months, the follow-up all data were collected again and crossover was performed. After another 3 months, during the final follow-up all these measures were repeated. RESULTS: In 87.5% patients, AVDopt were different than factory value. Cardiac output (CO), cardiac index (CI), and stroke volume (SV) were significantly (P < 0.001) higher in AVDopt group than in AVDfab group (CO: 6.0 ± 1.4 L/minute vs. 5.3 ± 1.2 L/minute; SV: 85.8 ± 25.7 mL vs.76.9 ± 22.5 mL; CI: 3.2 ± 0.7 L/minute/m(2) vs. 2.7 ± 0.6 L/minute/m(2) ). There was a statistical significant (P < 0.05) reduction of proBNP and NYHA class in patients with AVDopt compared to AVDfab (proBNP: 196.4 ± 144.7pg/mL vs. 269.4 ± 235.8 pg/mL; NYHA class: 1.7 ± 0.5 vs. 2.3 ± 0.6). Six-minute walking test was significantly (P < 0.05) higher in AVDopt group (409 ± 90 m) than in AVDfab group (362 ± 93 m). There were no statistically significant differences in echocardiographic parameters between AVDopt and AVDfab settings. CONCLUSION: Our study results suggest that AVD optimization in patients with DDD pacemaker with ICG improves hemodynamic when compared to the default factory settings. Furthermore, optimally programmed AVD reduces BNP and improves exercise tolerance and functional class.

Idiopathic Ventricular Tachycardia in the Presence of Triple-Vessel Coronary Artery Disease: A Case Report.

Exercise-induced ventricular tachycardia undergoes ischemia evaluation; however, it is important to identify idiopathic ventricular tachycardia in patients with concomitant coronary artery disease and radiofrequency ablations can be lifesaving. We report a case of exercise-induced right and left ventricular outflow tract ventricular tachycardia in a patient with triple vessel coronary artery disease.

Sinus Node Dysfunction Triggered by Tonsillar Abscess: Effects of Vagal Nerve Compression.

BACKGROUND Compression of the vagus nerve by a pharyngeal mass is a well-documented condition that can result in sinus node dysfunction (SND). However, there is scarce literature on extrinsic vagal nerve compression from a tonsillar abscess. CASE REPORT A 59-year-old woman with a history of asthma and chronic throat discomfort presented to the Emergency Department with bradycardia, palpitations, and voice changes. Following a shellfish allergy hospitalization, an otolaryngology evaluation revealed an enlarged right tonsil, recommending tonsillectomy, but scheduling challenges persisted. The patient reported mild throat pain, dysphagia, hoarseness, rhinorrhea, and exertional dyspnea and was admitted for the evaluation of peritonsillar mass. She was found to be bradycardic with a heart rate of 47, with an electrocardiogram revealing SND. Albuterol and ipratropium nebulizers, as well as dexamethasone and pantoprazole, were initiated. With this treatment, the patient symptomatically improved with a new heart rate of 68. She was discharged with outpatient appointments, but was unfortunately lost to follow-up. CONCLUSIONS This case reveals sinus node dysfunction resulting from extrinsic vagal nerve compression by a tonsillar abscess. Pressure on the vagus nerve can trigger bradycardia and low blood pressure, possibly due to compensatory overfiring of afferent vagal nerve signals from local mass effect. Early recognition and antibiotic treatment are essential to prevent cardiac complications. Clinicians must remain vigilant for such extrinsic causes, particularly in patients with chronic sore throat and cardiac symptoms. Further research and case reports are needed to deepen our understanding of this rare yet significant association.

Low-Power Long-Duration Versus High-Power Short-Duration Radiofrequency Ablation of the Atrioventricular Node.

BACKGROUND: Atrioventricular node (AVN) radiofrequency (RF) ablation is a highly effective treatment of atrial tachyarrhythmias that are resistant to other management modalities. To date, there is limited research that compares the properties of different RF ablation catheters. The current study aims to compare the effectiveness of several types of RF catheters in AVN ablation. METHODS: 66 patients, with a mean age of 73.27 years, underwent AVN RF ablation. The catheters used were categorized as: un-irrigated (UI), externally-irrigated (EI), and contact force-sensing with 10-20 grams of force. EI catheters were divided into two different settings: low-power long-duration (LPLD) (30W, 45°C, and 60 sec) and high-power short-duration (HPSD) (50W, 43°C, and 12 sec). We compared the success rate of the different RF catheters using logistic regression and lesion times using linear regression. RESULTS: The distribution of the types of catheters used is: UI in 48%, LPLD in 16%, and HPSD in 36% of patients. All ablation procedures were successful, with no immediate post-procedure complications. HPSD had a significantly shorter lesion time than UI catheters by 403.42 sec [-631.67, -175.17]. CONCLUSION: UI catheters, LPLD, and HPSD were equally safe and effective in ablation procedures. The HPSD catheter had a significantly shorter lesion time and, thus, overall decreased procedure time.

Severe Hypertrophic Cardiomyopathy Associated With Hydroxychloroquine in a Young Woman With Systemic Lupus Erythematosus: A Case Report and Review of the Literature.

The use of the antimalarial drug hydroxychloroquine is a standard treatment in patients with systemic lupus erythematosus. It helps reduce disease-associated damage, prevents disease flare, and improves overall survival. The mechanism of action of hydroxychloroquine includes interference with lysosomal degradation of cells leading to the accumulation of vacuoles. Retinopathy is a well-described adverse effect of hydroxychloroquine, thus requiring screening with an ophthalmologist after prolonged use. Although rarely reported, cardiac adverse effects of hydroxychloroquine can also occur. In this report, we present a case of a 23-year-old woman with systemic lupus erythematosus on hydroxychloroquine who presented with stroke possibly due to Libman-Sacks endocarditis and was found to have severe hypertrophic cardiomyopathy on transthoracic echocardiogram.

Successful Percutaneous Coronary Intervention in a Patient With Absent Right Coronary Artery Ostium: A Case Report and Literature Review.

Coronary artery anomalies present unique interventional challenges, particularly when associated with significant coronary artery disease. This case report contributes to the limited literature on congenital coronary artery anomalies, emphasizing the need for tailored approaches to optimize patient care. We present a case of a 70-year-old male with refractory angina and a rare congenital coronary anomaly characterized by the absence of the right coronary artery ostium, necessitating reliance on the left coronary system for myocardial perfusion. Cardiac catheterization revealed mid-left anterior descending artery stenosis, prompting percutaneous coronary intervention. Despite the anatomical complexities encountered, the procedure was successfully performed. This case underscores the importance of meticulous diagnostic evaluation, advanced imaging techniques, and a multidisciplinary approach to managing patients with rare coronary anomalies. This report also emphasizes the unique diagnostic and therapeutic considerations by providing a comprehensive literature review and identifying areas for further research to advance treatment strategies and improve outcomes.

A Case Report of Brugada Syndrome Associated With Physical Trauma.

Brugada syndrome is an autosomal dominant channelopathy that usually affects healthy young males without apparent structural heart disease. It is associated with a spectrum of variable and dynamic clinical manifestations, high risk of life-threatening ventricular arrhythmias, and sudden cardiac death. Our patient demonstrated transient and dynamic EKG changes of both type 1 (coved) and type 2 (saddleback) ST elevation, suggestive of the Brugada pattern that was associated with physical chest trauma and stressful situations. While common triggers like fever and certain drugs are well-recognized, this case illustrates the potential for physical stress and trauma to unmask or aggravate Brugada syndrome, albeit without definitive evidence for a causal link. Ultimately, this report underscores the importance of considering a broad differential diagnosis, including Brugada syndrome, in patients presenting with unexplained syncope or characteristic EKG changes, even when traditional triggers are absent.

Defibrillation waveform duration adjustment increases the proportion of acceptable defibrillation thresholds in patients implanted with single-coil defibrillation leads.

The aim of this study was to determine whether defibrillation waveform duration adjustment with single-coil defibrillation leads can be used to increase the proportion of patients with satisfactory defibrillation thresholds (DFTs). A retrospective analysis of the DFT levels for 105 patients with implantable cardioverter-defibrillator devices and a single-coil defibrillation lead was performed. Two groups of patients were compared: 34 patients who had undergone waveform tuning (group A) and 71 patients with a fixed-tilt waveform (group B). Additional data including demographics, etiology, New York Heart Association functional class, left ventricular ejection fraction, high-voltage lead impedance and medications were gathered to determine what effect these variables had on the DFT levels. Of the 34 patients who had undergone waveform adjustment (group A), 27 (79%) were found to have satisfactory DFTs, while 41 (58%) of the 71 patients with fixed-tilt devices (group B) had satisfactory DFTs. Waveform duration adjustment was found to significantly increase the proportion of patients with satisfactory DFTs (p = 0.03).

Nonischemic mitral regurgitation: prognostic value of nonsustained ventricular tachycardia after mitral valve surgery.

BACKGROUND: Nonsustained ventricular tachycardia (VT), frequent in unoperated severe mitral regurgitation (MR), confers mortality risk [sudden death (SD) and cardiac death (CD)]. The prognostic value of VT after mitral valve surgery (MVS) is unknown; we aimed to define this prognostic value and to assess its modulation by left (LV) and/or right (RV) ventricular ejection fraction (EF) for mortality after MVS. METHODS: In 57 patients (53% females, aged 58 ± 12 years) with severe MR prospectively followed before and after MVS, we performed 24-hour ambulatory electrocardiograms approximately annually. LVEF and RVEF were determined within 1 year after MVS by radionuclide cineangiography. RESULTS: During 9.52 ± 3.49 endpoint-free follow-up years, late postoperative CD occurred in 11 patients (7 SD, 4 heart failures). In univariable analysis, >1 VT episode after MVS predicted SD (p < 0.01) and CD (SD or heart failure; p < 0.04). Subnormal postoperative RVEF predicted CD (p < 0.04). When adjusted for preoperative age, gender, etiology or antiarrhythmics, both postoperative VT and RVEF predicted CD (p ≤ 0.05). When postoperative VT and RVEF were both in the multivariable model, only subnormal RVEF predicted CD (p < 0.04). Among those with normal RVEF, VT >1 episode predicted SD (p = 0.03). CONCLUSION: Postoperative VT and subnormal RVEF predict late postoperative deaths in nonischemic MR. Their assessment may aid patient management.

A Rare Case of a Panic Attack Inducing a Junctional Escape Rhythm on ECG.

We present a unique and rare case of a young female patient who presented with complaints typical of her prior panic attacks and was found to have a junctional escape rhythm on ECG. Upon resolution of her symptoms, a repeat ECG demonstrated a return to normal sinus rhythm. Given that alternative etiologies had been ruled out, it was postulated that her panic attack induced a transient junctional escape rhythm.

Transthyretin Cardiac Amyloidosis Presenting as Bradycardia, Renal Failure, Atrioventricular-Nodal Blockade, Shock, and Hyperkalemia (BRASH) Syndrome: A Case Report.

BRASH syndrome involves the chain of events resulting from the collective effects of Bradycardia, Renal failure, Atrioventricular (AV)-nodal blockade, Shock, and Hyperkalemia. BRASH syndrome can rapidly progress to cardiac arrest. Early recognition is crucial. We present a case of transthyretin cardiac amyloidosis (ATTR-CA) in an elderly woman who presented with BRASH syndrome shortly after an AV-nodal blocker was prescribed for atrial fibrillation.

Comparative Effectiveness of Various Radiofrequency Ablation Catheters in the Ablation of Typical Atrial Flutter.

INTRODUCTION: Although ablation of typical atrial flutter (AFL) can be easily achieved with radiofrequency energy (RF), no studies compare the effectiveness of different ablation catheters. Our study aimed to compare the efficacy of various types of ablation catheters in treating typical AFL. METHODS: We analyzed patients with AFL who underwent RF ablation by a single operator at our institution. Successful ablation was evidenced by a bidirectional conduction block (trans-isthmus conduction time ≥ 130 ms or double potentials ≥ 90 ms). Logistic regression was used to compare success rate and linear regression to compare lesion time. RESULTS: Out of 222 patients, only six did not meet the success criteria (2.7%). The catheters used were non-irrigated, large-tip, internally irrigated (Chili II Boston Scientific), and externally irrigated (non-force-sensing) catheters (Cool Path, Abbott). An externally irrigated force-sensing catheter (TactiCath, Abbott) was used with > 10 gm of force and (LPLD) setting (30 W- 45 °C- 60 s), and high-power short-duration (HPSD) setting (50 W- 43 °C - 12 s). No complications were encountered. The catheter type had no statistically significant association with ablation success. With the use of externally irrigated catheter with contract force-sensing and HPSD settings, statistically significantly shortening of lesion time was achieved 758.3 s, [CI - 1128.29, - 388.35 s] followed by LPLD by 419.0 s [CI - 808.49, - 29.47 s]. CONCLUSIONS: The typical atrial flutter radiofrequency ablation procedure had a high success rate, which was not influenced by the type of ablation catheter. Contact force ablation catheter and HPSD are associated with shorter total lesion time.

Embolic Phenomena of Libman-Sacks Endocarditis and Antiphospholipid Syndrome.

Patients with systemic lupus erythematosus (SLE) and antiphospholipid antibody syndrome (APS) are at high risk of developing arterial or venous thromboembolism and a state of systemic hypercoagulability. Libman-Sacks endocarditis (LSE) is a type of non-bacterial endocarditis usually seen in patients with systemic lupus erythematosus and antiphospholipid antibody syndrome. These vegetations dislodge easily and can cause profound neurological and systemic complications in the form of emboli. We describe one such case of a young woman with known SLE who presented with an acute middle cerebral artery (MCA) stroke and was found to have APS with extensive mitral valve vegetation, indicating Libman-Sacks endocarditis on echocardiography. Recognizing the increasing frequency of both APS and LSE in patients with SLE and screening patients, especially the younger population with SLE, for APS is vital. Furthermore, in those patients presenting with embolic events, echocardiography plays a key role as it can help expedite the diagnosis of LSE. Our case report also reiterates that warfarin, when compared to direct oral anticoagulants (DOAC), is superior in decreasing future embolic events.