Characteristic Electrocardiographic Findings Research Articles

The Comparative Assessment of Wellens' Syndrome With Proximal Left Anterior Descending Artery (LAD) Stenosis Versus Right Coronary Artery (RCA) or Circumflex Coronary Artery Stenosis and Its Prevalence: A Systematic Review.

Wellens'syndrome is well-known for its critical stenosis of the proximal left anterior descending artery (LAD) with characteristic electrocardiographic findings of biphasic or deeply inverted T waves in V2-V6 under specific diagnostic criteria. Although the syndrome is known as a high-grade LAD lesion, its sequence of events can also be seen with the right coronary artery (RCA) and the left circumflex artery (LCX). This systemic review attempts to expand on these findings while analyzing the prevalence of Wellens' syndrome with the RCA and/or the circumflex artery. This study also comparatively indicated that Wellens'syndrome is seen in RCA and circumflex arterystenoses when present; the indication of the same medical management is warranted for effective treatment and survival. We extracted and analyzed 24 case reports each with an atypical presentation of acute coronary syndrome (ACS) and specific Wellens'syndrome pattern of electrocardiogram (ECG) presentation with critical stenosis in the LAD, RCA, and left circumflex artery.The risk of bias assessment was undertaken using internal risk analysis by utilizing medical libraries and certain search phrases to find research articles with the involvement of the LAD as opposed to the RCA and LCX in Wellens' syndrome. Based on the number of respective primary research articles found, a bias calculation was done on the reported respective coronary artery involvement. The finding of our systemic review confirms that Wellens'syndrome is a precordial lead disease with T wave abnormalities that presentwithcritical stenosis of not only the LAD but also the RCA and circumflex artery. The result of our systemic review affirmed that although most Wellens'syndrome cases reported involve the stenosis of the LAD, the critical occlusion of the RCA and/or the circumflex artery was found with Wellens'syndrome pattern of ECG presentation, meaning that the sequence of events is not limited to the proximal LAD.

A supraventricular tachycardia with a possible accessory pathway in a young Labrador Retriever

A supraventricular tachycardia was diagnosed in a 3-year-old male Labrador Retriever. Based on patient signalment and characteristic electrocardiographic findings, an accessory pathway bypassing the normal atrioventricular nodal pathway causing an atrioventricular reciprocating tachycardia was a differential diagnosis. However, an alternative diagnosis of a focal atrial tachycardia was another possibility. The dog was successfully treated short-term with intravenous diltiazem, and long-term with modified release oral diltiazem. This report shows the utility of the electrocardiogram in the diagnosis of a supraventricular tachycardia, as well as the medical management for this emergency case.

When Lithium Hurts

Ebstein anomaly (EA) is a congenital defect of the tricuspid valve (TV) and the right ventricle (RV) in which the attachments of the septal and posterior valve leaflets are apically displaced. The latter creates 3 morphologic components inside the right heart, namely the right atrium proper, the atrialized RV, and the functional RV. This rare anomaly accounts for <1.5% of all congenital heart diseases. The current opinion among authors is that it is a genetically heterogeneous condition caused by failure of delamination of the TV leaflets from the underlying myocardium and the interventricular septum. Its characteristic electrocardiographic findings include tall, broad, right atrial P waves, prolonged PR intervals, and deep Q waves in the right precordial leads. Echocardiography is currently the best technique for diagnosing this anomaly, although cardiac magnetic resonance imaging is also gaining traction as an alternative modality. The management strategies for EA correlate with the age of the patient, severity of the heart disease, and/or associated cardiac abnormalities. TV repair, rather than valve replacement, is preferred because of its favorable long-term prognosis. Nevertheless, a large, randomized study is still needed to compare the different valve repair techniques used in patients with EA.

Catheter Ablation of Tachyarrhythmias From the Aortic Sinuses of Valsalva

The aortic root is at the center of the heart. Each of the aortic sinuses of Valsalva, positioned at the base of the aortic root, is in contact with the atrial myocardium and/or ventricular myocardium at their bases, which enables mapping and ablating of some ventricular arrhythmias with an outflow tract origin and supraventricular tachycardias (ie, atrial tachycardia, accessory pathways) from the aortic sinuses of Valsalva. These arrhythmias have characteristic electrocardiographic findings associated with their origins, and almost all are difficult to ablate from an atrial or ventricular endocardial site. Site-specific and potential complications, such as a coronary artery occlusion or atrioventricular block, can occur with catheter ablation at the aortic sinuses of Valsalva. Therefore, accurate diagnosis and proper ablation at the aortic sinuses of Valsalva are required for a cure. This review describes the anatomic features of the aortic sinuses of Valsalva and focuses on the diagnosis and radiofrequency catheter ablation of arrhythmias that can be ablated from this site. (Circ J 2012; 76: 791-800).

Wellens syndrome: a life-saving diagnosis

The diagnosis of acute coronary syndrome relies on clinical history, electrocardiographic (ECG) changes, and cardiac biomarkers; but within the spectrum of acute coronary syndrome, there exist subtle presentations that cannot afford to be overlooked. Wellens syndrome is one such example, in which a patient can present with both ECG changes that are not classic for myocardial ischemia and negative cardiac biomarkers. The characteristic ECG findings associated with Wellens syndrome consist of deep, symmetric T-wave inversions in the anterior precordial leads. However, Wellens syndrome can also present as biphasic T-wave inversions in those same ECG leads. The associated critical stenosis of the proximal left anterior descending artery carries an immediately life-threatening prognosis if not recognized promptly (Am Heart J. 1982;103[4 Pt 2]:730-736). We describe a case of a less common manifestation of Wellens syndrome (type 1) followed by a discussion of its implications and management.

Electrocardiography in Noonan syndrome PTPN11 gene mutation—phenotype characterization

Noonan syndrome is a developmental disorder with distinctive facial features, short stature and cardiac abnormalities. In this cross-sectional study, we evaluated characteristic electrocardiographic (ECG) findings and cardiac abnormalities in 84 patients with Noonan syndrome, 56 (67%) of who were positive for a PTPN11 mutation. As reported previously, pulmonary stenosis was the most common cardiac abnormality, followed by atrial septal defect and hypertrophic cardiomyopathy. The ECG showed at least one characteristic finding in 50% of cases including left axis deviation in 38 (45%), small R waves in the left precordial leads in 20 (24%) and an abnormal Q wave in 5 (6%) patients with Noonan syndrome. A wide QRS complex was not detected in any of these patients. The characteristic ECG findings of Noonan syndrome patients were not associated with a PTPN11 gene mutation, or with a (specific) cardiac anomaly. We conclude that there are characteristic ECG findings in Noonan syndrome, but the ECG pattern is neither a useful tool for the phenotype characterization of a PTPN11 mutation, nor for the presence or type of cardiac abnormality.

Electrocardiographic algorithms for predicting the complexity of coronary artery lesions in ST-segment elevation myocardial infarction in ED

Objective In reperfusion strategy for ST-elevation myocardial infarction (STEMI), emergency surgical bypass grafting might be considered for patients with significant multivessel coronary diseases complicated by cardiogenic shock. The culprit lesions in STEMI can be predicted from electrocardiographic (ECG) findings. However, whether the complexity of coronary artery lesions in STEMI can be predicted from characteristic ECG findings remained unclear. Materials and Methods The initial 12-lead ECG parameters in each lead recording from patients with STEMI receiving primary percutaneous coronary intervention within 12 hours were retrospectively analyzed. A sequential ECG algorithm was developed to predict the complexity of coronary artery lesions. Results In patients with inferior wall STEMI, the presence of the following 2-step criteria indicated 3-vessel disease (3VD), with a sensitivity of 92.1% and a specificity of 81.8%: (1) ST depression or flat T wave in leads V 5 or V 6; and (2) ST elevation of more than 2 mm in at least 1 of II, III, aVF, or Q (loss of septal r) without ST elevation in aVR. In patients with anterior wall STEMI, the following criteria indicated 3VD: (1) ST elevation of more than 4 mm in at least 1 of the precordial leads and combined with QRS interval of more than 120 ms; then (2) a flat T wave over aVR, or aVL combined with flat T wave ST depression over lead I or Q wave over all leads II, III, and aVF. This algorithm detects patients with 3VD with a sensitivity of 76.5% and a specificity of 100%. However, when the whole algorithm is completed, the sensitivity can reach up to 88.4% and the specificity can still be 100%. Conclusion By using this ECG algorithm, 3VD might be distinguished early from single-vessel disease in patients with STEMI for appropriate reperfusion strategy.

Effect of age and overweight on the QT interval and the prevalence of long QT syndrome in children

The change in QT interval with age during childhood of normal children and children with long QT syndrome (LQTS) and the effects of body mass index on the QT interval have not been studied in detail. The prevalence of LQTS in children is not well known. We measured 3 consecutive QT and RR intervals in 4,655 children. Their electrocardiograms along with their height and weight were recorded when they were in the first grade in 1994 and again when they were in the seventh grade in 2000. The QT interval was corrected by Bazett’s formula. The longer corrected QT intervals in female subjects than male subjects start at elementary school age, earlier than previously reported. Overweight did not have an impact on the uncorrected or corrected QT interval. None of the 4 children diagnosed with LQTS in the seventh grade had characteristic electrocardiographic findings of LQTS in the first grade. All 4 are nonfamilial cases. The prevalence of LQTS in children was found to be 1 of 1,164. These data suggest that abnormal electrocardiographic phenotypes in children with nonfamilial LQTS may appear during the elementary school year. The longer QT intervals in female subjects than male subjects start at the same period. No correlation was found between obesity and length of the QT interval. Finally, the prevalence of LQTS in children is greater than previously suspected.

Instructions to authors

Clinical CardiologyVolume 22, Issue 3 p. 225-225 EditorFree Access Instructions to authors First published: 03 February 2009 https://doi.org/10.1002/clc.4960220312AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. References 1 Zuckerman R, Cabrera CE, Fishleder BL, Sodi-Pallares D: The electrocardiogram in chronic cor pulmonale. Am Heart J 1948; 35: 421– 425 2 Spodick DH: Electrocardiographic studies in pulmonary disease. I. Electrocardiographic abnormalities in diffuse lung disease. Circulation 1959; 20: 1067– 1072 3 Spodick DH: Electrocardiographic studies in pulmonary disease. II. Establishment of criteria for the electrocardiographic inference of diffuse lung disease. Circulation. 1959; 20: 1073– 1074 4 Spodick DH, Hauger-Klevene JH, Tyler JM, Muench G, Dorr CA: The electrocardiogram in pulmonary emphysema: Relationship of characteristic electrocardiographic findings to severity of disease as measured by the degree of airway obstruction. Am Rev Resp Dis 1963; 88: 14– 19 5 Shah NS, Koller SM, Janower ML, Spodick DH: Diaphragm levels of determinants of P axis in restrictive vs. obstructive pulmonary disease. Chest 1995; 107: 697– 700 6 Spodick DH: Pericardial Macro and Microanatomy. In DH Spodick: The Pericardium: A Comprehensive Textbook, p. 7– 14. New York: Marcel Dekker, 1997 Volume22, Issue3March 1999Pages 225-225 ReferencesRelatedInformation

Multiple different missense mutations in the pore region of HERG in patients with long QT syndrome.

Long QT syndrome (LQTS), is an inherited cardiac disorder in which ventricular tachyarrhythmias predispose affected individuals to syncope, seizures, and sudden death. Characteristic electrocardiographic findings include a prolonged QT interval, T wave alternans, and notched T waves. We have screened LQTS patients from 89 families for mutations in the pore region of HERG , the K+ channel gene previously associated with chromosome 7-linked LQT2. In six unrelated LQTS kindreds, single-strand conformation polymorphism analyses identified aberrant conformers in all affected family members. These conformers were not seen in over 100 unaffected, unrelated control individuals, suggesting that they represent pathogenic LQTS mutations. DNA sequence analyses of the aberrant conformers demonstrated that they reflect five different missense mutations: V612L, A614V, N629D, N629S, and N633S. The missense mutation A614V was found in two unrelated families. Further functional studies will be required to determine what effect each of these changes may have on HERG channel function.

Electrocardiographic criteria for the diagnosis of the left septal fascicular block and its frequency among primarily elderly hospitalized patients

Characteristic electrocardiographic findings of the left septal fascicular block consist of a prominent anterior QRS force. Therefore, the following criteria were proposed for the diagnosis of left septal fascicular block, based on the normal limits of the R and S waves and R/S of V1 and V2. (1) Right ventricular hypertrophy, complete right bundle branch block, preexcitation (Type A), high posterior infarction, hypertrophic cardiomyopathy and abnormality of the thorax or intrathoracic tissues which might cause marked counterclockwise rotation around the longitudinal axis of the heart, should be excluded. (2) One of the following two criteria should be satisfied. (i) R/Sv1 greater than 2, and Rv1 greater than or equal to 5 mm, (ii) R/Sv2 greater than 2, and Rv2 greater than or equal to 15 mm, or Sv2 less than 5 mm. The frequency of left septal fascicular block diagnosed by these criteria was 3.5% among all patients of a hospital mainly consisting of elderly patients. This frequency was less than that of the left anterior fascicular block or complete right bundle branch block, but it was higher than that of the complete left bundle branch block or bilateral bundle branch block.

Cardiac arrhythmia and suspect cardiomyopathy in a boxer dog

A 3 year old Boxer dog was presented with a history of syncope and an irregular heart heat. An arrhythmia characterised by ventricular premature contractions was detected and was thought to cause the syncopal episodes. On the basis of the age, breed and the characteristic electrocardiographic findings, a diagnosis of Boxer Cardiomyopathy was made. The dog was treated with procainamide 500 mg every 8 hours to control the arrythmia and there were no further syncopal episodes in the subsequent 13 months.

The Electrocardiographic Features of Acute Cardiac Tamponade

To test the hypothesis that the electrocardiogram of cardiac rupture is due to acute cardiac tamponade, 27 episodes of cardiac tamponade were produced in ten open-chest dogs. During continuous monitoring of the electrocardiogram and the arterial and venous pressures, 10-30 cc of autologous, heparinized blood, or one of several other solutions, were intermittently infused into the pericardial sac until no effective blood pressure was recorded. The characteristic electrocardiographic findings of acute cardiac tamponade were peaked P waves, decrease of QRS complex voltage, left axis deviation of the QRS complex, deep T wave inversions, and ST-segment change. With the appearance of electromechanical dissociation, there was a sudden, vagally-mediated bradycardia. Because these changes are similar to those observed at the time of cardiac rupture, it was concluded that the electrocardiographic manifestations of cardiac rupture could be attributed to acute cardiac tamponade.

Diagnostic value of electrocardiographic abnormalities observed in subjects accidentally exposed to cold

Electrocardiograms were recorded in 5 patients accidentally exposed to cold. All 5 patients came from either a poorly heated room or the open air. Usually there was some alteration of mental function or ability to walk, resulting in prolonged exposure to cold. The characteristic electrocardiographic findings in hypothermia are bradycardia, atrial fibrillation, muscle tremor artifact, prolongation of the QRS complex with “J” or “Osborn” waves and prolongation of the Q-T interval. In these patients changes ranged from mild to severe. Follow-up tracings were obtained in 3. The electrocardiogram can be of considerable value in revealing hypothermic states with low “core” temperature. Severe electrocardiographic changes are easily detected and usually are associated with a grave underlying illness and poor prognosis. Milder degrees of hypothermia result in recognizable electrocardiographic changes that can be helpful in evaluating a recorded low rectal temperature.

Influence of aldosterone and angiotensin II on endotoxin shock in the primate.

SummarySevere endotoxin shock in monkeys resulted in hypotension, oliguria or anuria, hyperkalemia and death. No characteristic electrocardiographic findings were elicited. Aldosterone and angiotensin II were employed alone and in combination in attempts to reverse the shock. The most favorable results were obtained with a combination of the steroid and pressor drug. As in canine endotoxin shock, aldosterone markedly potentiated the pressor action of angiotensin II. Optimum results were correlated with the amount of aldosterone administered.

The cardiotoxic effects of hyperpotassemia and its treatment.

Hyperpotassemia is common and its possible presence should be considered in any patient with electrolyte imbalance, particularly in the presence of renal insufficiency. The clinical diagnosis can be established by the characteristic electrocardiographic findings and confirmed by estimation of serum potassium, Hyperpotassemia kills primarily by its cardiotoxic effect, and a vigorous therapeutic regimen can often be lifesaving. Active therapy includes use of alkalizing solutions, especially molar sodium lactate and calcium; use of glucose and insulin; and removal of potassium by gastric or intestinal suction, cation exchange resins, and dialysis with the artificial kidney.

Ulcerative colitis with hypopotassemia

Summary A case of severe ulcerative colitis is presented in which potassium deficiencywas one of the principal features. This resulted in low serum-potassium values and characteristic electrocardiographic findings. The clinical disturbances associated with the potassium deficiency are described. The degree of abdominal distention and ileus which complicated the course of the illness, and the mental changes with which it was associated, were apparently related to the depletion of the body potassium. Potassium replacement therapy and return of the serum potassium level to normal were followed by marked improvement of the patient, correction of the ileus, and disappearance of the mental disturbances. The events that occurred in this patient emphasize the need for careful observation of serum potassium levels while treating patients with severe ulcerative