Electrocardiogram and left atrial abnormality: Design of an observational study to clarify diagnostic criteria

Background

The criteria applied for diagnosis of left atrial (LA) abnormality using electrocardiogram (ECG) have high specificity but low sensitivity. In fact, some authors have suggested classifying P‐wave anomalies associated with LA abnormality and interatrial block as “atrial abnormalities.” The most widely known ECG criteria for LA abnormality include P‐wave duration, morphology and voltage of P wave in inferior leads, presence of P‐wave terminal force in V₁ (PtfV₁), and P‐wave axis and area. PtfV₁ has also been reported to vary according to misplacement of the V₁ and V₂ electrodes.

Methods

The objective of this observational cohort study is to determine the degree of correlation between ECG criteria for LA abnormality and left atrium volume and functionality, as determined by speckle tracking echocardiography. The study also aims to investigate the correlation between these echocardiographic parameters and PtfV₁ value by placing the V₁ and V₂ electrodes in the second, third, and fourth intercostal spaces.

Results and Conclusions

Our results could help to clarify whether the decrease in left atrial deformity, which is currently considered a surrogate target of fibrosis, correlates better with ECG criteria for LA abnormality than atrial volumes.

Old teaching tools should not be forgotten: The value of the Lewis ladder diagram in understanding bigeminal rhythms

As medical education evolves, some traditional teaching methods often get forgotten. For generations, the Lewis ladder diagram (LLD) has helped students understand the mechanisms of cardiac arrhythmias and conduction disorders. Similarly, clinicians have used LLDs to communicate their proposed mechanisms to their colleagues and trainees. In this article, we revisit this technique of constructing the LLD and demonstrate this process by describing the mechanisms of various bigeminal rhythms.

Long-Term Radiotherapy-Induced Cardiac Complications: A Case Report

Patient: Male, 48

Final Diagnosis: Late cardiac complications postradiotherapy

Symptoms: Chest pain • dyspnea • syncope

Medication: —

Clinical Procedure: Diagnostic and therapeutic techniques in cardiology

Specialty: Cardiology

Epsilon wave: A review of historical aspects

The epsilon wave of the electrocardiogram (ECG) together with fragmented QRS (fQRS), the terminal conduction delay, incomplete right bundle branch block (IRBBB) and complete/advanced RBBB (CRBBB) of peripheral origin are part of a spectrum of ventricular depolarization abnormalities of arrhythmogenic cardiomyopathy(AC). Although the epsilon wave is considered a major diagnostic criterion for AC since 2010 (AC Task Force Criteria), its diagnostic value is limited because it is a sign of the later stage of the disease. It would be more appropriate to say that the epsilon wave is a “hallmark” of AC, but is of low diagnostic sensitivity. Although the epsilon wave has high specificity for AC, it can be present in other pathological conditions. In this update we will cover the nomenclature, association with disease states and electrocardiographic aspects of the epsilon wave.

Role of echocardiography in a patient with suspected acute pulmonary embolism: a case report

Background

Approximately half of pulmonary embolism cases are diagnosed in an emergency context. The classic symptoms of pulmonary embolism are absent in intensive care unit patients who are under sedation and on mechanical ventilation. In this scenario, after the development of sudden, severe hypotension, pulmonary embolism must be considered and included in a differential diagnosis according to the cause of admission. Echocardiography may be of further help in a differential diagnosis of the cause of shock.

Case presentation

We present a case of a 44-year-old Caucasian man who was admitted to the intensive care unit with a diagnosis of community-acquired pneumonia and respiratory failure and who required invasive mechanical ventilation. During admission, the patient developed sudden, severe hypotension that was refractory to treatment. An adequate diagnosis with transthoracic echocardiography was unachievable because of a poor echocardiographic window. However, the combined use of electrocardiography and transesophageal echocardiography established pulmonary embolism as a high-probability diagnosis based on findings of right ventricular pressure overload and right ventricular dysfunction. The unfavorable hemodynamic situation of the patient prevented his transfer to carry out other complementary tests that could confirm the diagnosis of pulmonary embolism. Fibrinolytic and anticoagulant therapies were administered immediately, and a favorable clinical outcome was achieved.

Conclusion

This case highlights the fundamental role that echocardiography played in a patient in the intensive care unit who presented with shock secondary to pulmonary embolism with an unfavorable hemodynamic situation and in whom an unnecessary transfer to perform other complementary diagnostic tests was avoided. The combined use of electrocardiography and echocardiography provided a complete differential diagnosis, identifying the cause of shock and allowing the initiation of specific treatment without further delay. Knowledge of the echocardiographic results that are characteristic of pulmonary embolism can aid in the diagnosis.

Electronic supplementary material

The online version of this article (10.1186/s13256-019-1994-y) contains supplementary material, which is available to authorized users.

Advanced interatrial block is a surrogate for left atrial strain reduction which predicts atrial fibrillation and stroke

BACKGROUND

The association between advanced interatrial block (aIAB) and atrial fibrillation (AF) is known as "Bayes' Syndrome." There is little information on the prognostic role that new speckle tracking echocardiographic (STE) imaging techniques could play in it. We have examined the relationship between left atrial (LA) STE and the prediction of new-onset AF and/or stroke in IAB patients.

METHODS

This is an observational prospective and unicentric cohort study with 98 outpatients: 55 (56.2%) controls with normal ECG without IAB, 21 (21.4%) with partial IAB (pIAB) and 22 (22.4%) with aIAB. The end point was new-onset AF, ischemic stroke and the composite of both.

RESULTS

During a mean follow-up of 1.9 (1.7-2.3) years, 20 patients presented the end point (18 new-onset AF and two strokes): 8 (14.5%) in the control group, 3 (14.3%) in pIAB and 9 (40.9%) in aIAB, p = 0.03. In multivariable comprehensive Cox regression analyses, a decrease in absolute value of strain rate during the booster pump function phase (SRa) was the only variable independently related to the appearance in the evolution of the end point, in the first model (age, P-wave duration and SRa): HR 19.9 (95% CI, 3.12-127.5), p = 0.002 and in the second (age, presence of aIAB and SRa): HR 24.2 (95% CI, 3.15-185.4), p = 0.002.

CONCLUSIONS

In patients with IAB, a decrease in absolute value of LA SRa with STE predicts new-onset AF and ischemic stroke. Future studies should confirm our results and assess the prognostic usefulness of LA STE in patients with IAB.

Clinical manifestations, diagnosis, and treatment of ischemic mitral regurgitation: a review

Ischemic mitral regurgitation (IMR) is a frequent complication after acute myocardial infarction (AMI) associated with a worse prognosis. The pathophysiological mechanisms of IMR are not fully understood, but it is known to be a complex process in which ventricular remodelling is the main causal factor. The various imaging techniques in cardiology and echocardiography fundamentally have contributed significantly to clarify the mechanisms that cause and progressively aggravate IMR. At present, different therapeutic options, the most important of which are cardio-surgical, address this problem. Nowadays the improvement in cardiac surgery and transcatheter therapies, have shown a therapeutic advance in IMR management. IMR is a predictor of poor prognosis in patients with heart failure and depressed left ventricular (LV) systolic function. However, it remains controversial whether mitral regurgitation (MR) in these patients is a consequence of dilation and dysfunction of the LV, or whether it contributes to worsening the prognosis of the ventricular dysfunction. Given that echocardiography has a fundamental reference role in the identification, graduation of severity and evaluation of the therapeutics used in the treatment of MR, we are going to focus on it over the rest of the imaging techniques. In contrast to primary MR the benefits of mitral surgery in patients with secondary MR are uncertain. Therefore, we will comment fundamentally on the role of mitral surgery in patients with IMR, with an update of the different surgical interventions available, without forgetting to mention the other therapeutic options currently available.

Acute inferior myocardial infarction with right ventricular involvement and several clinical-electrocardiographic markers of poor prognosis

Right ventricular involvement in inferior myocardial infarction is a marker of poor prognosis. We present a case of a 62-year-old man with very recent onset of acute chest pain and cardiac shock with the triad of elevated jugular venous pressure, distension of the jugular veins on inspiration, and clear lung fields. In addition, the admission electrocardiogram showed a slurring J wave or lambda-like wave and conspicuous ST segment depression in several leads, predominantly in the lateral precordial (V4-V6), all clinical-electrocardiographic features of ominous prognosis.

Compression of the right coronary artery by an aortic pseudoaneurysm after infective endocarditis: an unusual case of myocardial ischemia

A 61-year-old male with a prosthetic St Jude aortic valve size 24 presented with heart failure symptoms and minimal-effort angina. Eleven months earlier, the patient had undergone cardiac surgery because of an aortic root dilatation and bicuspid aortic valve with severe regurgitation secondary to infectious endocarditis by Coxiela burnetii and coronary artery disease in the left circumflex coronary artery. Then, a prosthesis valve and a saphenous bypass graft to the left circumflex coronary artery were placed. The patient was admitted to the Cardiology Department of Hospital Universitario de Canarias, Tenerife, Spain and a transthoracic echocardiography was performed that showed severe paraprosthetic aortic regurgitation and an aortic pseudoaneurysm. The 64-slice multidetector computed tomography confirmed the pseudoaneurysm, originating from the right sinus of Valsalva, with a compression of the native right coronary artery and a normal saphenous bypass graft. On the basis of these findings, we performed surgical treatment with a favorable postoperative evolution. In our case, results from complementary cardiac imaging techniques were crucial for patient management. The multidetector computed tomography allowed for a confident diagnosis of an unusual mechanism of coronary ischemia.

Bayes Syndrome and Imaging Techniques

BACKGROUND

Interatrial block (IAB) is due to disruption in the Bachmann region (BR). According to whether interatrial electrical conduction is delayed or completely blocked through the BR, it can be classified as IAB of first, second or third degree. On the surface electrocardiogram, a P wave ≥ 120 ms (partial IAB) is observed or associated to the prolongation of the P wave with a biphasic (positive / negative) morphology in the inferior leads (advanced IAB). Bayes syndrome is defined as an advanced IAB associated with atrial arrhythmia, more specifically atrial fibrillation. Objective and Conclusion: The purpose of this review is to describe the latest evidence about an entity considered an anatomical and electrical substrate with its own name, which may be a predictor of supraventricular arrhythmia and cardioembolic cerebrovascular accidents, as well as the role of new imaging techniques, such as echocardiographic strain and cardiac magnetic resonance imaging, in characterizing atrial alterations associated with this syndrome and generally in the study of anatomy and atrial function.

Differential diagnosis of rSr' pattern in leads V1 -V2. Comprehensive review and proposed algorithm

One of the more frequent dilemmas in ECG interpretation is the differential diagnosis of an rSr' pattern in leads V1 -V2 . We often face this finding in asymptomatic and otherwise healthy individuals and the causes may vary from benign nonpathological variants to severe or life-threatening heart diseases, such as Brugada syndrome or arrhythmogenic right ventricular dysplasia. In other cases, a normal variant of rSr' pattern can be misinterpreted as pathological after the occurrence of certain clinical events such as cardiac arrest or syncope of unknown cause. In this review we analyze in detail all the possible conditions, both benign and pathological that may explain the presence of this electrocardiographic pattern. We also propose a simple electrocardiographic algorithm for differential diagnosis.

Syncope and polymorphic ventricular tachycardia in the setting of a febrile illness

An asymptomatic woman with no clinical history consulted for pneumonia-induced fever; she then presented episodes of syncope due to polymorphic ventricular tachycardia and ECG alterations compatible with Brugada syndrome. Genetic studies showed no alterations in the SCN5A gene but other polymorphisms were observed. Further genetic studies are required to elucidate the pathophysiological mechanisms of fever and the function of sodium channels.

Left ventricular ballooning syndrome due to vasospasm of the middle portion of the left anterior descending coronary artery

We report a case that shows vasospasm to be one of the mechanisms responsible for left ventricular ballooning syndrome. Our case suggests that identical ventriculographic findings in patients with tako-tsubo syndrome and those with coronary vasospasm of a long left anterior descending artery coronary artery may be due to a common etiology.

Technical mistakes during the acquisition of the electrocardiogram

In addition to knowledge of normal and pathological patterns, the correct interpretation of electrocardiographic (ECG) recordings requires the use of acquisition procedures according to approved standards. Most manuals on standard electrocardiography devote little attention to inadequate ECG recordings. In this article, we present the most frequent ECG patterns resulting from errors in limb and precordial lead placement, artifacts in 12-lead ECG as well as inadequate filter application; we also review alternative systems to the standard ECG, which may help minimize errors.

Effects of inadequate low-pass filter application

Some technical aspects in the ECG recording, although basic, are not well enough known. In this short communication we present two examples in which the low-pass filter attenuates or eliminates electrocardiographic signals which are important from the clinical point of view.

An unusual case of electrode misplacement: left arm and V(2) electrode reversal

Accidental interchange between precordial and limb leads, although unusual, can be possible given that some of them share the same color. We present the case where interchange of V(2) and left arm cables produced significant electrocardiographic abnormalities, which created many doubts and discussion within the clinical team.