Clinical Presentation and Risk Stratification of Pulmonary Embolism.

Pulmonary embolism (PE) presents with a spectrum of symptoms, ranging from asymptomatic cases to life-threatening events. Common symptoms include sudden dyspnea, chest pain, limb swelling, syncope, and hemoptysis. Clinical presentation varies based on thrombus burden, demographics, and time to presentation. Diagnostic evaluation involves assessing symptoms, physical examination findings, and utilizing laboratory tests, including D-dimer. Risk stratification using tools like Wells score, Pulmonary Embolism Severity Index, and Hestia criteria aids in determining the severity of PE. PE is categorized based on hemodynamic status, temporal patterns, and anatomic locations of emboli to guide in making treatment decisions. Risk stratification plays a crucial role in directing management strategies, with elderly and comorbid individuals at higher risk. Early identification and appropriate risk stratification are essential for effective management of PE. As we delve into this review article, we aim to enhance the knowledge base surrounding PE, contributing to improved patient outcomes through informed decision-making in clinical practice.

The Clinical Association between Carbon Monoxide Poisoning and Myocardial Injury as Measured by Elevated Troponin I Levels.

Carbon monoxide (CO) poisoning accounts for over 50,000 estimated emergency room visits and approximately 1200 deaths per year in the US. Despite the high prevalence, there is a paucity of data looking at the association between laboratory biomarkers and clinical outcomes. Our study investigates the association between myocardial injury as assessed by increased troponin levels and its effect on in-hospital outcomes in CO poisoning. A total of 900 sequential charts of patients presenting with CO poisoning between 1 January 2012, and 31 August 2019, at our tertiary center with regional hyperbaric chamber and burn unit, were reviewed. Of the 900, a total of 488 patients had elevated carboxyhemoglobin levels. Of these 488 patients, 119 (24.4%) also had blood troponin levels measured. Patients were stratified based on the presence or absence of myocardial injury as evidenced by highly sensitive serum troponin I (TnI) level > 0.5 ng/mL to determine if a correlation exists relating to myocardial injury and risk of major adverse events. Mean age was 51.2 years, 58.8% were males, 35.3% were non-White, and 10.1% were intentional CO poisonings. Comorbidities included hypertension: 37%, diabetes: 21%, smoking: 21%, hyperlipidemia: 17.6%, coronary artery disease: 11.8%, asthma: 5.9%, heart failure: 5%, atrial fibrillation: 4.2%, and chronic obstructive pulmonary disease: 4.2%. Myocardial injury occurred in 22 patients (18.5%) and was associated with increased likelihood of requiring intensive care admission (54.5% vs. 20.6%, p = 0.002) and intubation (40.9% vs. 14.4%, p = 0.008). TnI elevation was associated with higher in-hospital mortality (p = 0.008, OR 21.3) compared to patients without TnI elevation. Older age was independently associated with increased in-hospital mortality (p = 0.03, OR 1.08). When controlling for age, in-hospital mortality remained statistically significant (p = 0.01, OR 21.37). No significant difference was found with respect to age, comorbidities, gender, race, ethnicity, or hospital length of stay in patients with and without myocardial injury. Myocardial injury induced by CO exposure occurs frequently and adversely affects clinical outcomes. Further research is needed to help guide physicians in the management of CO poisoning and associated myocardial injury to improve patient outcomes.

Correction: Farshadmand et al. Utility of Cardiac Power Hemodynamic Measurements in the Evaluation and Risk Stratification of Cardiovascular Conditions. Healthcare 2022, 10, 2417.

Zachary Lowy was not included as an author in the original publication [...].

Presence of Permanent Pacemakers: Implications for Elderly Patients Presenting with Traumatic Injuries.

Background: The presence of permanent pacemakers (PPM) is common among the elderly population. Trauma literature has shown that the inability to augment cardiac output by at least 30% after injury portends a higher mortality. The presence of a PPM may be a surrogate marker to identify patients who are unable to increase cardiac output. We aimed to evaluate the association between the presence of PPM and clinical outcomes in elderly patients presenting with traumatic injuries. Methods: A total of 4505 patients aged ≥65 years admitted with acute trauma from 2009 to 2019 at our Level I Trauma center were evaluated and stratified into two groups using propensity matching on age, sex, injury severity score (ISS), and year of admission based on the presence of PPM. Logistic regression was performed to analyze the impact of the presence of PPM on mortality, surgical intensive care unit (SICU) admission, operative intervention, and length of stay. Prevalence of cardiovascular comorbidities was compared using χ2 analysis. Results: Data from 208 patients with PPM and 208 propensity-matched controls were evaluated. Charlson Comorbidity Index, mechanism of injury, intensive care unit admission, and rate of operative intervention were comparable in the two groups. PPM patients had more coronary artery disease (p=0.04), heart failure with reduced ejection fraction (p=0.003), atrial fibrillation (AF, p<0.0001), and antithrombotic use (p<0.0001). We found no association between mortality amongst the groups after controlling for influencing variables (OR=2.1 (0.97 to 4.74), p=0.061). Patient characteristics associated with survival included female sex (p=0.009), lower ISS (p<0.0001), lower revised trauma score (p<0.0001), and lower SICU admission (p=0.001). Conclusion: Our study shows no association between mortality among patients with PPM admitted for treatment of trauma. Presence of a PPM may be an indicator of cardiovascular disease, but this does not translate into increased risk in the modern era of trauma management in our patient population. Level of evidence: Level III.

Transient Ischemic Attack in a Patient With Poland Syndrome With Dextrocardia.

This report discusses the case of a patient with a past medical history of Poland syndrome and dextrocardia who was admitted for a transient ischemic attack. Poland syndrome is a rare genetic condition characterized by underdevelopment of chest wall musculature that presents with a variety of associations that may or may not be present in each case. This case report intends to discuss a unique presentation of Poland syndrome with dextrocardia, one of the rare conditions associated with Poland syndrome, as well as the treatment of Poland syndrome as a whole and possible associated complications.

Utility of Cardiac Power Hemodynamic Measurements in the Evaluation and Risk Stratification of Cardiovascular Conditions.

Despite numerous advancements in prevention, diagnosis and treatment, cardiovascular disease has remained the leading cause of mortality globally for the past 20 years. Part of the explanation for this trend is persistent difficulty in determining the severity of cardiac conditions in order to allow for the deployment of prompt therapies. This review seeks to determine the prognostic importance of cardiac power (CP) measurements, including cardiac power output (CPO) and cardiac power index (CPI), in various cardiac pathologies. CP was evaluated across respective disease-state categories which include cardiogenic shock (CS), septic shock, transcatheter aortic valve replacement (TAVR), heart failure (HF), post-myocardial infarction (MI), critical cardiac illness (CCI) and an "other" category. Literature review was undertaken of articles discussing CP in various conditions and this review found utility and prognostic significance in the evaluation of TAVR patients with a significant correlation between one-year mortality and CPI; in HF patients showing CPI and CPO as valuable tools to assess cardiac function in the acute setting; and, additionally, CPO was found to be an essential tool in patients with CCI, as the literature showed that CPO was statistically correlated with mortality. Cardiac power and the derived measures obtained from this relatively easily obtained variable can allow for essential estimations of prognostic outcomes in cardiac patients.

"To Fix a Broken Heart": An Unusual Case of Infective Endocarditis Involving the Mitral Valve With Perforation and Hemodynamic Instability.

Infective endocarditis (IE), commonly caused by Staphylococcus aureus, can affect multiple cardiac structures and lead to significant morbidity and mortality. We present a case of IE with extensive mitral valve involvement causing perforation and hemodynamic compromise. A 66-year-old Caucasian female presented to the emergency department for progressive altered mental status and lethargy. The patient and family denied history of intravenous drug use (IVDU) on interview. Physical exam revealed tachypnea, tachycardia, lethargy, and fluctuance in the right antecubital fossa draining serous fluid. Initial studies revealed a urinary tract infection, patchy bilateral opacities on chest x-ray, hypoxic respiratory failure, elevated lactate and cardiac markers, leukocytosis, and positive urine toxicology for opioid and benzodiazepine. She was intubated and admitted to the ICU, and later developed acute respiratory distress syndrome with requirement for vasopressors. Antibiotics were started, and blood cultures ultimately grew methicillin-sensitive S. aureus. Coronavirus disease 2019 (COVID-19) results were negative. Cardiology was consulted for elevated cardiac markers that were due to myocardial injury in the setting of septic shock. A transthoracic echocardiogram showed a large mobile mass on the anterior mitral leaflet. Further evaluation with transesophageal echocardiogram revealed a large, mobile, and centrally necrotic vegetation on the medial portion of the mitral annulus extending to both the anterior and posterior leaflets. Doppler of the valve showed holosystolic retrograde ejection into the left atrium confirming a perforation. The patient was transferred urgently to a cardiothoracic surgery capable center for operative intervention on the mitral valve. IE is most commonly caused by S. aureus and seen in highest rates among patients with a prosthetic valve, congenital heart disease, and intracardiac device. However, roughly 50% of IE occurs in patients without any valvular disease. Other risk factors include IVDU, valvular disease, and prior history of endocarditis. Clinical diagnosis of IE is made using the Duke's criteria, with echocardiogram and bacteremia playing a major role. The initial management involves empiric antibiotics until a pathogen is identified. Surgical consult is also suggested, and indications for surgery include heart failure due to valve dysfunction, uncontrolled infection, prevention of embolism, and hemodynamic compromise. Prompt recognition and intervention is crucial in the prevention of mortality in patients with IE leading to mitral perforation and hemodynamic compromise.

Determining the clinical significance of computer interpreted electrocardiography conclusions.

BACKGROUND: Computerized electrocardiogram (EKG) interpretation technology was developed in the mid-20th century, but its use continues to be controversial. This study aims to determine clinical factors which indicate greater odds of clinical significance of an abnormal computerized EKG interpretation. METHODS: The inclusion criteria for this retrospective study were patients who underwent outpatient echocardiography for the indication of an abnormal EKG and had an EKG abnormality diagnosed by the computerized EKG system. Qualifying patients had the results of their computerized EKG, echocardiogram, and charted patient characteristics collected. Computerized diagnoses and patient characteristics were assessed to determine if they were associated with increasing or decreasing the odds of an echocardiographic abnormality via logistic regression. Chi-square and t-test analyses were used for categorical and continuous variables, respectively. Odds ratios are presented as odds ratio [95% confidence interval]. A P-value of ≤ 0.05 was considered statistically significant. RESULTS: A total of 515 patients were included in this study. The population was 59% women with an average age of 57 ± 16 years, and a mean BMI of 30.1 ± 7.3 kg/m2. Patients with echocardiographic abnormalities tended to have more cardiac risk factors than patients without abnormalities. In our final odds ratio model consisting of both patient characteristics and EKG diagnoses, age, coronary disease (CAD), and diabetes mellitus (DM) increased the odds of an echocardiographic abnormality (1.04 [1.02-1.06], 2.68 [1.41-5.09], and 1.75 [1.01-3.04], respectively). That model noted low QRS voltage decreased the odds of an abnormal echocardiogram (0.31 [0.10-0.91]). CONCLUSION: Our findings suggest that in patients with an abnormal computerized EKG reading, the specific factors of older age, CAD, and DM are associated with higher odds of abnormalities on follow-up echocardiography. These results, plus practitioner overreading, can be used to determine more appropriate management when faced with an abnormal computerized EKG diagnosis.

Impact of cardiologist intervention on guideline-directed use of statin therapy.

BACKGROUND: Statins have an important and well-established role in the prevention of atherosclerotic cardiovascular disease (ASCVD). However, several studies have reported widespread underuse of statins in various practice settings and populations. Review of relevant literature reveals opportunities for improvement in the implementation of guideline-directed statin therapy (GDST). AIM: To examine the impact of cardiologist intervention on the use of GDST in the ambulatory setting. METHODS: Patients with at least one encounter at the adult Internal Medicine Clinic (IMC) and/or Cardiology Clinic (CC), who had an available serum cholesterol test performed, were evaluated. The 2 comparison groups were defined as: (1) Patients only seen by IMC; and (2) Patients seen by both IMC and CC. Patients were excluded if variables needed for calculation of ASCVD risk scores were lacking, and if demographic information lacked guideline-directed treatment recommendations. Data were analyzed using student t-tests or χ 2, as appropriate. Analysis of Variance was used to compare rates of adherence to GDST. RESULTS: A total of 268 patients met the inclusion criteria for this study; 211 in the IMC group and 57 in the IMC-CC group. Overall, 56% of patients were female, mean age 56 years (± 10.65, SD), 22% Black or African American, 56% Hispanic/Latino, 14% had clinical ASCVD, 13% current smokers, 66% diabetic and 63% hypertensive. Statin use was observed in 55% (n = 147/268) of the entire patient cohort. In the IMC-CC group, 73.6% (n = 42/57) of patients were prescribed statin therapy compared to 50.7% (n = 107/211) of patients in the IMC group (P = 0.002). In terms of appropriate statin use based on guidelines, there was no statistical difference between groups [IMC-CC group 61.4% (n = 35/57) vs IMC group, 55.5% (n = 117/211), P = 0.421]. Patients in the IMC-CC group were older, had more cardiac risk factors and had higher proportions of non-white patients compared to the IMC group (P < 0.02, all). CONCLUSION: Although overall use of GDST was suboptimal, there was no statistical difference in appropriate statin use based on guidelines between groups managed by general internists alone or co-managed with a cardiologist. These findings highlight the need to design and implement strategies to improve adherence rates to GDST across all specialties.

Impact of Beta-Blockade on Cardiac Events in Patients with Chronic Severe Nonischemic Mitral Regurgitation.

OBJECTIVES: The aim of this study was to examine the impact of beta-blockade on cardiac events among patients with initially asymptomatic chronic severe nonischemic mitral valve regurgitation (MR). METHODS: Data from 52 consecutive patients in our prospective natural history study of isolated chronic severe nonischemic MR were assessed post hoc over 19 years to examine the relation of chronic beta-blockade use to subsequent cardiac events (death or indications for mitral valve surgery, MVS). At entry, all patients were free of surgical indications; 9 received beta-blockers. Cardiac event rate differences were analyzed by Kaplan-Meier log rank comparison. RESULTS: During follow-up, cardiac events included sudden death (1), heart failure (8), atrial fibrillation (6), left ventricular dimensions at systole ≥4.5 cm (11), left ventricular ejection fraction <60% (6), right ventricular ejection fraction <35% (2), and a combination of cardiac events (7). The cardiac event risk was 4-fold higher among patients receiving beta-blockers (average annual risk = 60.6%) versus those not receiving beta-blockers (average annual risk = 15.2%; p = 0.001). These effects remained statistically significant (p = 0.005) when analysis was adjusted for other baseline covariates. CONCLUSIONS: Beta-blockade appears to confer an increased risk of sudden cardiac death or indications for MVS among patients with chronic severe nonischemic MR. Randomized trials are needed to confirm these findings.

Deep Vein Thrombosis of the Left Leg: A Case of May-Thurner Syndrome.

A 56-year-old woman presented with gradually worsening shortness of breath associated with dull left leg pain over 5 days. She denied any recent travel, recent surgeries or immobilization. CT pulmonary angiography and CT venography revealed multiple bilateral pulmonary emboli and extensive left pelvic and left lower extremity deep vein thromboses. Contrast-enhanced CT showed that the right common iliac artery crossed the left common iliac vein and compressed it externally, indicative of May-Thurner syndrome. Catheter-directed thrombolysis of the left lower extremity was performed and heparin infusion was started. The patient also underwent left iliac vein balloon angioplasty with stenting and infra-renal inferior vena cava filter placement via the jugular approach to prevent further embolization. LEARNING POINTS: May-Thurner syndrome (MTS) should be suspected in patients in their second to fourth decade of life presenting with unprovoked deep venous thrombosis of the left leg.An iliac venogram is the diagnostic test of choice for MTS.MTS is treated only when it is symptomatic. The goal of treatment is to remove the clot to prevent post-thrombotic syndrome and to repair the anatomical defect.A stent was successfully deployed in the iliac vein of our patient and restoration of blood flow resulted in a dramatic improvement in the patient's symptoms.

Duration of Dual Antiplatelet Therapy Following Drug-Eluting Stent Implantation: A Systematic Review and Meta-analysis of Randomized Controlled Trials.

To evaluate the efficacy and safety of long-duration dual antiplatelet therapy (L-DAPT) compared to short-duration dual antiplatelet therapy (S-DAPT) after drug-eluting stent implantation. We searched Medline, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) to identify randomized controlled trials assessing the clinical effect of L-DAPT vs S-DAPT after drug-eluting stent. Efficacy end points were all-cause mortality, cardiac mortality, myocardial infarction (MI), stent thrombosis (ST), and target vessel revascularization (TVR). Safety end points were TIMI major bleeding and stroke. Event rates were compared using a random-effects model. We identified 11 randomized controlled trials in which 33,520 patients were randomized to S-DAPT (N = 16,687) and L-DAPT (n = 16,833), respectively. Compared with L-DAPT, S-DAPT was associated with higher rate of MI and lower rate of TIMI major bleeding (1.40 [1.08-1.81] and 0.60 [0.41-0.89], respectively), without any significant differences in the rate of all-cause mortality, cardiac mortality, ST, TVR, and stroke (0.88 [0.75-1.04], 0.98 [0.79-1.22], 1.54 [0.95-2.50], 0.99 [0.73-1.34], and 1.01 [0.78-1.32], respectively). Our results showed that compared with L-DAPT, S-DAPT was associated with higher rate of MI and lower rate of major bleeding without any significant difference in the rates of all-cause mortality, cardiac mortality, ST, TVR, and stroke.

Cardiac resynchronization therapy in heart failure patients with less severe left ventricular dysfunction.

Cardiac resynchronization therapy is beneficial in heart failure patients with LVEF ≤35% and electrical dyssynchrony. However, its effects among patients with less severe LV dysfunction have not been established. Recent post-hoc analyses of landmark CRT trials suggest that CRT benefit may be present in patients with LVEF >35% and is associated with improvement in cardiac reverse remodelling, all-cause mortality, and need for heart failure hospitalizations. This review summarizes the currently available literature regarding the potential impact of CRT in patients with more modest reductions in LVEF.

Relation of indirect vasodilator use to prognosis in patients with chronic severe mitral regurgitation.

OBJECTIVES: The relation of indirect vasodilator use to cardiac events (CE) is undefined for chronic severe nonischemic mitral regurgitation (MR). The aim of this study was to resolve this knowledge deficiency. METHODS: Data from 52 consecutive patients in our prospective natural history study with isolated chronic severe nonischemic MR were assessed post hoc over 19 years to examine the relation of indirect vasodilator use to subsequent CE (death or indications for valve surgery). At entry, no patient had surgical indications, 14% had hypertension (HTN) and 7 chronically received vasodilators (5 angiotensin-converting enzyme inhibitor, 1 receptor blocker and 1 α-adrenergic blocker). CE differences were assessed by log-rank comparison of Kaplan-Meier curves. RESULTS: During follow-up, CE included sudden death (1 patient), heart failure (7 patients), atrial fibrillation (6 patients), left ventricular (LV) systolic dimension >4.5 cm (12 patients), LV ejection fraction (EF) <60% (7 patients), right ventricular EF <35% (2 patients) and combination CE (7 patients). Overall, vasodilator use did not predict CE (not significant). However, patients without HTN had higher CE rates with vasodilators than without (p = 0.007), while those with HTN and vasodilators had lower CE rates than those without vasodilators (p = 0.04). CONCLUSION: Vasodilator use appears to confer no survival benefit in patients with chronic severe MR. The small number of patients with HTN precludes conclusions about modulation of vasodilator effect by HTN. Randomized trials are needed to conclusively evaluate this association.

Usefulness of preoperative exercise tolerance to predict late survival and symptom persistence after surgery for chronic nonischemic mitral regurgitation.

Exercise duration during exercise treadmill testing (ETT) predicts long-term outcome among asymptomatic patients with mitral regurgitation. However, the prognostic value of preoperative exercise duration in patients who undergo mitral valve surgery is unknown. We examined findings among 45 prospectively followed (average 9.2 ± 4.3 years) patients (aged 54.8 ± 12.0 years, 45% men) with chronic isolated severe MR who underwent ETT before mitral valve surgery to test the hypotheses that exercise duration predicts long-term postoperative survival and persistent symptoms within 2 years after operation. During follow-up, 11 patients died; of these, 8 had persistent symptoms. Among patients who exercised >7 minutes, average annual postoperative all-cause and cardiovascular mortality risks were 0.75% (both endpoints) versus 5.4% and 4.8%, respectively, versus those who exercised ≤7 minutes (p = 0.003 all-cause, p = 0.007 cardiovascular). Exercise duration predicted postoperative deaths (p <.02 all cause, p <.04 cardiovascular) even when analysis was adjusted for preoperative variations in age, gender, medications, history of atrial fibrillation, and peak exercise heart rates. Other ETT, echocardiographic, and clinical variables were not independently associated with these outcomes when exercise duration was considered in the analysis. Preoperative exercise duration also predicted postoperative (New York Heart Association functional class ≥II) symptom persistence (p = 0.012), whereas other ETT, echocardiographic and clinical variables did not (NS, all). In conclusion, among patients who undergo surgery for chronic nonischemic mitral regurgitation, preoperative exercise duration, unlike many commonly used descriptors, is useful for predicting postoperative mortality and symptom persistence. Future research should determine whether interventions to improve exercise tolerance before mitral valve surgery can modify these postoperative outcomes.

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.

Resveratrol mediates anti-atherogenic effects on cholesterol flux in human macrophages and endothelium via PPARγ and adenosine.

Resveratrol is a bioactive molecule used in dietary supplements and herbal medicines and consumed worldwide. Known cardioprotective and anti-inflammatory properties of resveratrol have spurred investigation of the mechanisms involved. The present study explored potential atheroprotective actions of resveratrol on cholesterol metabolism in cells of the arterial wall, including human macrophages and arterial endothelium. Using QRT-PCR and Western blotting techniques, we measured expression of the proteins involved in reverse cholesterol transport (ABCA1, ABCG1 and SR-B1) and the scavenger receptors responsible for uptake of modified cholesterol (CD36, SR-A1 and LOX-1). We analyzed the effect of resveratrol on apoA-1-and HDL-mediated cholesterol efflux in human THP-1 macrophages. The effect of resveratrol on oxLDL internalization and foam cell formation were evaluated using confocal and light microscopy. Our data indicate that resveratrol regulates expression of major proteins involved in cholesterol transport, promotes apoA-1 and HDL-mediated efflux, downregulates oxLDL uptake and diminishes foam cell formation. Mechanistically, resveratrol effects were dependent upon PPAR-γ and adenosine 2A receptor pathways. For the first time we demonstrate that resveratrol regulates expression of the cholesterol metabolizing enzyme cytochrome P450 27-hydroxylase, providing efficient cholesterol elimination via formation of oxysterols. This study establishes that resveratrol attenuates lipid accumulation in cultured human macrophages via effects on cholesterol transport. Further in vivo studies are needed to determine whether resveratrol may be an additional resource available to reduce lipid deposition and atherosclerosis in humans.

[Use of non-contact mapping to localise distant from endocardium origin of atrial tachycardia].

A 65 year-old woman developed tachycardia and hypotension during haemodialysis. The non-contact mapping system was used to localise the origin of focal atrial tachycardia, and showed a remote from the endocardium focus. We discuss techniques that are helpful in identifying the origin, the area of preferential conduction, and the endocardial breakthrough of tachycardia.