Pseudo-pacemaker syndrome with prolonged PR interval: A narrative review.

Pseudo-pacemaker syndrome (PPMS) is a rare complication of first-degree atrio-ventricular (AV) block in which a very prolonged PR interval causes AV dyssynchrony and subsequent symptoms of hemodynamic instability in the absence of an implanted pacemaker. The aim of this manuscript was to describe a unique case of PPMS and to provide a comprehensive review of the topic to help clinicians in the diagnosis and management of this condition. Through systematic research on PubMed, Google Scholar, EBSCO, and Ovid MEDLINE and using the search strings "pseudo-pacemaker syndrome" and "symptomatic first-degree AV block," we identified 14 articles accounting for 17 cases of PPMS, including our case report. The most common age group for PPMS was middle-aged and young adults, with an average age of 47 years. Palpitations were the most common presenting symptom and four main etiologies of PPMS were identified, as follows: (1) Idiopathic PPMS with evidence of impaired conduction over the AV node (20% of cases), (2) PPMS associated with reversable inflammatory causes (13%) or (3) associated with iatrogenic surgical or interventional procedures leading to the permanent damage of the normal AV conduction system (20%), and, finally, (4) PPM related to dual AV nodal physiology (DAVNP) as a primary finding (27%) or occurring after fast or slow pathway ablation for treatment of AV nodal re-entrant tachycardia (AVNRT) (20%). Treatment should be patient-tailored and based on the specific etiology once identified. However, the treatment of PPMS due to DAVNP without AVNRT presentation is yet to be clarified.

Early repolarization pattern in an ethnically diverse population: Increased risk in Hispanics.

BACKGROUND: Early repolarization (ER) pattern on ECG is associated with an increased mortality in Caucasians. This study analyzed the association between ER pattern and all-cause mortality in a population of multiple ethnicities. METHODS: A total of 20 000 individuals were randomly selected and their ECGs were analyzed for ER pattern using the 2015 consensus: end-QRS notching or slurring with a J-point (Jp) ≥0.1 mV in contiguous inferior or lateral leads. Exclusion criteria were age <18, QRS duration of ≥120 ms, and acute myocardial infarction. Kaplan-Meier survival curves were used to assess crude survival, and multivariable logistic regression models were used to determine predictors of all-cause mortality. RESULTS: A total of 17 901 patients with a mean age of 53 met inclusion criteria. Individuals were 62% female, 14% White, 37% Black, 40% Hispanic, and 9% other. Median follow-up time was 6.4 years. ER pattern was noted in 995 (5.6%) patients. Jp ≥2 mm was noted in 282 (1.6%) patients. In those with ER pattern and Jp ≥1 mm, there was no difference in mortality when compared to individuals without Jp elevation (odds ratio [OR]: 0.962, 95% confidence of interval [CI]: 0.819-1.131). Patients with Jp ≥2 mm had a significantly increased all-cause mortality (OR: 1.333, 95% CI: 1.009-1.742). This increased mortality was also significant in Hispanic patients with Jp ≥2 mm (OR: 1.584, 95% CI: 1.003-2.502). CONCLUSION: ER pattern with Jp ≥2 mm is associated with increased mortality in a multiethnic population, apparently driven by an increased risk in Hispanics.

Takotsubo Cardiomyopathy in a Young Patient Presenting as Cardiac Arrest and Cardiogenic Shock.

Takotsubo cardiomyopathy (TC) is a reversible cardiac disorder that rarely results in serious morbidity and mortality. Cardiogenic shock and cardiac arrest can occur in patients with TC. In this case report, we present the case of a 31-year-old woman with no significant comorbidities who suffered cardiac arrest due to TC and subsequent cardiogenic shock that required inotropic and vasopressor support. The patient's condition progressively improved, and her cardiac function recovered within a few weeks. This case illustrates the importance of recognizing TC as a significant cause of otherwise unexplained cardiac arrest and highlights the need for evidence-based guidelines for treating cardiogenic shock in this setting.

Not All ST Elevation Is STEMI: Brugada Phenocopy Induced by Hyperkalemia.

Brugada syndrome (BrS) is a hereditary channelopathy associated with malignant ventricular arrhythmia and sudden death in individuals with a structurally normal heart. It is characterized by an ST-segment elevation in the precordial leads. Brugada phenocopy (BrP) is a term given to conditions that could result in ST morphologies identical to those found in Brugada syndrome (Brugada pattern electrocardiogram (EKG) changes) without the actual channelopathy responsible for Brugada syndrome. BrP is a rare EKG manifestation of hyperkalemia, commonly seen at high serum levels of potassium, and associated with malignant arrhythmia. Here, we present a case with Brugada pattern EKG changes associated with hyperkalemia and metabolic acidosis, which normalized after correcting the electrolyte abnormalities. In this case, we also wanted to highlight that not all ST-segment elevation is due to myocardial infarction (MI). In young patients with no coronary artery disease (CAD) risk factors, other potential ST elevation causes should be considered.

A Devastating Tear: Atypical Presentation of Aortic Dissection Discovered on Echocardiography.

Acute aortic dissection (AAD) is a serious medical problem that requires prompt recognition in order to prevent deadly complications. Nevertheless, making the diagnosis can often be challenging. The clinical signs and symptoms of AAD may vary depending on the location of the dissection, leading to subtle differences in the initial patient presentation. Moreover, the classically described signs of blood pressure disparity, pulse deficit, or the presence of a diastolic murmur are often absent. Here, we report a challenging case of AAD in which the patient presented with acute substernal chest pain that resolved after a short period and was associated with hypotension. His bilateral upper and lower extremities were well perfused with symmetrical, palpable pulses. The initial point-of-care ultrasound (POCUS) showed a small pericardial effusion, and a follow-up echocardiogram revealed an ascending aortic flap with aortic root dilation diagnostic of AAD. Our aim is to shed light on the challenge of diagnosing AAD.

A Head-to Head Comparison of Machine Learning Algorithms for Identification of Implanted Cardiac Devices.

Application of artificial intelligence techniques in medicine has rapidly expanded in recent years. Two algorithms for identification of cardiac implantable electronic devices using chest radiography were recently developed: The PacemakerID algorithm, available as a mobile phone application (PIDa) and a web platform (PIDw) and The Pacemaker Identification with Neural Networks (PPMnn), available via web platform. In this study, we assessed the relative accuracy of these algorithms. The machine learning algorithms (PIDa, PIDw, PPMnn) were used to predict device manufacturer using chest X-rays for patients with implanted devices. Each prediction was considered correct if predicted certainty was >75%. For comparative purposes, accuracy of each prediction was compared to the result using the CARDIA-X algorithm. 500 X-rays were included from a convenience sample. Raw accuracy was PIDa 89%, PIDw 73%, PPMnn 71% and CARDIA-X 85%. In conclusion, machine learning algorithms for identification of cardiac devices are accurate at determining device manufacturer, have capacity for improved accuracy with additional training sets and can utilize simple user interfaces. These algorithms have clinical utility in limiting potential infectious exposures and facilitate rapid identification of devices as needed for device reprogramming.

Changes in atrial fibrillation admissions following daylight saving time transitions.

BACKGROUND: Daylight saving time (DST) imposes a twice-yearly hour shift. The transitions to and from DST are associated with decreases in sleep quality and environmental hazards. Detrimental health effects include increased incidence of acute myocardial infarction (MI) following the springtime transition and increased ischemic stroke following both DST transitions. Conditions effecting sleep are known to provoke atrial fibrillation (AF), however the effect of DST transitions on AF are unknown. METHODS: Admitted patients aged 18-100 with primary ICD9 code of AF between 2009 and 2016 were included. The number of admissions was compiled and means were compared for the Monday to Thursday period and the entire seven day interval following each DST transition and the entire year for the entire cohort and separated by gender. Significance was determined with Wilcoxon nonparametric tests. RESULTS: Admission data for 6089 patients were included, with mean age of 68 years and 53% female. A significant increase was found in mean AF admissions over the Monday to Thursday period (3.09 vs 2.47 admissions/day [adm/d], P = 0.017) and entire week (2.48 vs 2.09 adm/d, P = 0.025) following the DST spring transition compared to the yearly mean. When separated by gender, women exhibited an increase in AF admissions following the DST spring transition (1.78 vs 1.28 adm/d for Monday to Thursday period, P = 0.036 and 1.38 vs 1.11 adm/d for entire week, P = 0.050) while a non-significant increase was seen in men. No significant differences were found following the autumn transition for the entire cohort or when separated by gender. CONCLUSION: An increase in AF hospital admissions was found following the DST springtime transition. When separated by gender, this finding persisted only among women. This finding adds to evidence of negative health effects associated with DST transitions and factors that contribute to AF episodes.

Atrial Fibrillation and the Weekend Effect Regarding Cardioversion, Length of Stay, Readmission, and Mortality.

BACKGROUND: The weekend effect is a phenomenon in which worse outcomes have been found to occur over the weekend. This has been investigated in the context of stroke, ST-elevation myocardial infarction, and pulmonary embolism among others. Atrial fibrillation (AF) is the most common sustained arrhythmia, and admissions for AF have been increasing. However, few studies exist investigating the existence of a weekend effect regarding AF. Previous studies have been limited by a pragmatic but unrealistic definition of the weekend starting at midnight on Friday and ending midnight on Sunday. In addition, the studies that exist have conflicting data regarding outcomes of mortality and length of stay (LOS). METHODS: Over a 5-year period, 3233 patients with a primary diagnosis of AF were admitted to an academic center. A retrospective analysis was performed to determine rates of cardioversion, 30-day readmission, 30-day mortality, LOS, and time to cardioversion among patients admitted over the weekend compared with those admitted during the work week. Weekend was defined as the 48-hour period, including Saturday and Sunday. RESULTS: Baseline demographics and common risk factors were found to be equivalent in weekend admissions compared with weekday admissions. These characteristics were found to be equivalent in those who underwent cardioversion and those who did not. There was no statistically significant difference between groups in odds of cardioversion, 30-day readmission, or 30-day mortality. Difference in mean LOS and mean time to cardioversion was not statistically significant between groups. CONCLUSION: In conclusion, a weekend effect was not identified regarding AF in an academic hospital.

Relation of Body Mass Index to Development of Atrial Fibrillation in Hispanics, Blacks, and Non-Hispanic Whites.

No previous studies have examined the interaction between body mass index (BMI) and race/ethnicity with the risk of atrial fibrillation (AF). We retrospectively followed 48,323 persons free of AF (43% Hispanic, 37% black, and 20% white; median age 60 years) for subsequent incident AF (ascertained from electrocardiograms). BMI categories included very severely underweight (BMI <15 kg/m2), severely underweight (BMI 15.1 to 15.9 kg/m2), underweight (BMI 16 to 18.4 kg/m2), normal (BMI 18.5 to 24.9 kg/m2), overweight (BMI 25.0 to 29.9 kg/m2), moderately obese (BMI 30 to 34.9 kg/m2), severely obese (BMI 35 to 39.9 kg/m2), and very severely obese (BMI >40 kg/m2). Cox regression analysis controlled for baseline covariates: heart failure, gender, age, treatment for hypertension, diabetes, PR length, systolic blood pressure, left ventricular hypertrophy, socioeconomic status, use of ß blockers, calcium channel blockers, and digoxin. Over a follow-up of 13 years, 4,744 AF cases occurred. BMI in units of 10 was associated with the development of AF (adjusted hazard ratio 1.088, 95% confidence interval 1.048 to 1.130, p <0.01). When stratified by race/ethnicity, non-Hispanic whites compared with blacks and Hispanics had a higher risk of developing AF, noted in those whom BMI classes were overweight to severely obese. In conclusion, our study demonstrates that there exists a relation between obesity and race/ethnicity for the development of AF. Non-Hispanic whites had a higher risk of developing AF compared with blacks and Hispanics.

Increasing Awareness on Health Care Access in Florida: A Community-Based Medical-Legal Practicum Project.

PROBLEM: Service learning and experiential coursework has become a requirement for medical students and law students. Advocacy for the underinsured and uninsured is of ethical importance to both the practice of law and medicine, however engaging professional students in meaningful advocacy work with community partners can be challenging. PURPOSE: The article describes a partnership between medical and law students in a community-based service learning project to promote health care access. KEY POINTS: Law and medical students at Florida International University partnered with community members and Florida Legal Services to collect patient narratives, disseminate information on Medicaid expansion to community members, and present patient stories to state lawmakers. CONCLUSIONS: The medical and law students learned about each other's professional roles and gained skills in interviewing, and legislative and policy advocacy through this service learning project by providing legislative testimony to key stakeholders and community education on Medicaid expansion.

Radioprotective lightweight caps in the interventional cardiology setting: a randomised controlled trial (PROTECT).

AIMS: The aim of this study was to test the radioprotection efficacy and comfort of newer bilayer barium sulphate-bismuth oxide composite (XPF) caps in an interventional cardiology setting. METHODS AND RESULTS: Operators were randomly assigned to wear standard fabric (n=59), 0.3 mm (n=74), or 0.5 mm (n=64) lead-equivalent XPF caps. Radiation doses were measured by using dosimeters placed outside and underneath the caps. Wearing comfort was assessed at the end of each measurement on a visual analogue scale (VAS) (0-100, with 100 indicating optimal comfort). Procedural data did not differ between the XPF and standard groups. Mean standard, XPF 0.3 mm, and XPF 0.5 mm cap weights were 12.5 g, 118.4 g, and 123.7 g, respectively. VAS comfort ratings of the standard and XPF caps did not differ significantly (p=0.272). The mean radiation protection was 12.0%, 95% CI: 4.9-19.1% (standard caps, n=35), 91.5%, 95% CI: 87.4-95.6% (XPF 0.3 mm caps, n=45) and 97.1%, 95% CI: 92.5-100% (XPF 0.5 mm caps, n=44) (p≤0.001 for all group comparisons). Using the XPF caps, a cumulative total radiation dose reduction by almost factor 10 was evident (272 procedures, 22,310 µSv outside the XPF caps, 2,770 µSv inside the caps). CONCLUSIONS: Lightweight XPF caps show comparable comfort to standard fabric caps, but provide substantial radiation protection during fluoroscopy-guided cardiac interventions.

Prospective comparison of palpation versus ultrasound-guided radial access for cardiac catheterization.

BACKGROUND: Radial access is increasingly used for both diagnostic and interventional cardiac procedures. Prospective data comparing ultrasound- versus palpation-guided radial catheterization are largely lacking. METHODS: In this prospective, single-center study, a total of 183 consecutive patients scheduled for transradial cardiac catheterization by an experienced interventionalist were assigned 1:1 to either palpation- or ultrasound-guided radial access. Demographic and procedure parameters were prospectively recorded. RESULTS: Baseline demographic and clinical parameters did not differ significantly between the ultrasound group (n = 92) and palpation group (n = 91). The initial radial catheterization success rate (87% vs 86.8%; P=.999) and time to access (47 seconds [interquartile range (IQR), 20-90 seconds] versus 31 seconds [IQR, 20-75 seconds]; P=.179) did not differ between the ultrasound and palpation groups, respectively. Pulse quality (absent, weak, strong) was independently associated with access failure in both groups (P<.001). Obesity was associated with access failure in the palpation group (P=.005), but not in the ultrasound group (P=.544). In 3/12 cases (25%) in the ultrasound group and 2/6 cases (33%) in the palpation group, the operator was able to establish radial access using the alternative method (P=.710). If palpation-guided radial access failed, an additional ultrasound-guided attempt before crossover to femoral access was associated with a shorter overall time to access (525 seconds [IQR, 462-567 seconds] versus 744 seconds [IQR, 722-788 seconds]; P=.016). CONCLUSIONS: Ultrasound-guided radial access seems to provide no substantial additional benefit over palpation-guided access alone. Attempting the alternative guiding methods to establish radial access before crossover to femoral access seems to be a reasonable approach.