A three-dimensional computed model of ST segment abnormality in type 1 Brugada Pattern: A key role of right ventricular outflow tract orientation?

Since its first description, Brugada Syndrome is characterized by definite ECG abnormalities (J wave, elevated ST segment) confined in right precordial leads. Brugada Pattern (BP) could be found in one or more right precordial leads, at conventional or higher intercostal spaces. A recent study, conducted by our group, reported that slightly less than one half of patients with type 1 BP show a definite ST segment depression (≥0.1 mV with duration ≥ 0.08 s) in the inferior leads. With these premises, 4 distinct ST abnormalities phenotypes can be recognizable in Type 1 BP. We speculated the key role of orientation of right ventricular outflow tract in the thorax, particularly the inclination of anterior wall compared to the sternum, contributing to the determination of these various ECG phenotypes. An interactive program, ECGsim, able to simulate ECG appearance in several anatomical and electrical models, confirmed this assumption. This computed model affirmed the strict relationship between ST segment depression in the inferior leads and the ST segment elevation in right precordial leads, typical of type 1 BP. A horizontal right ventricular outflow tract, in fact, gives raise to abnormal BP vector directed both superiorly and anteriorly, explaining, at the same time, typical BP appearance in right precordial leads and ST segment depression in the inferior leads.

The effects of gender on electrical therapies for the heart: physiology, epidemiology, and access to therapies.

The difference between men and women is clear even just by looking at an electrocardiogram: females present higher resting heart rate, a shorter QRS complex length and greater corrected QT interval. The development of these differences from pubertal age onward suggests that sexual hormones play a key role, although their effect is far from being completely understood. Different incidences between sexes have been reported for many arrhythmias, both ventricular and supraventricular, and also for sudden cardiac death. Moreover, arrhythmias are an important issue during pregnancy, both for diagnosis and treatment. Interestingly, cardiovascular structural and electrophysiological remodelling promoted by exercise training enhances this 'gender effect'. Despite all these relevant issues, we lack gender specific recommendations in the current guidelines for electrical therapies for heart rhythm disorders and heart failure. Even more, we continue to see that fewer women are included in clinical trials and are less referred than men for these treatments.

Electrocardiographic and Electrophysiological Characteristics of Atrial Tachycardia With Early Activation Close to the His-Bundle.

INTRODUCTION: Radiofrequency (RF) ablation of atrial tachycardia (AT) with earliest activation at the His-bundle may be associated with the risk of AV block, and detection of this AT origin using the electrocardiogram (ECG) would be helpful in planning ablation. Aim of this study was to characterize the P-wave morphology and intracardiac electrograms at the successful ablation site for this group of ATs. METHODS: All consecutive patients undergoing ablation for AT with earliest activation at the His-bundle were included. Twelve-lead ECG and intracardiac electrograms were analyzed. RESULTS: A total of 33 patients underwent successful ablation. The P-wave and the PR interval during AT (cycle length 460 ± 88, range 360-670 milliseconds) were significantly shorter compared to sinus rhythm 87 ± 18 vs. 117 ± 23 and 131 ± 37 vs. 170 ± 47 milliseconds, respectively, P < 0.01. In 28 patients (85%), the P-wave was biphasic (-/+) or triphasic (+/-/+) in the precordial leads, especially V4 -V6 , and in 25 patients (76%) it was biphasic (-/+) or triphasic (+/-/+) in the inferior leads. RF was delivered at the following locations: noncoronary aortic cusp (NCC) in 24 patients, antero-septal left atrium in 4, supero-septal right atrium in 3, left coronary cusp in 1, and between the right coronary cusp and the NCC in 1. Atrial bipolar electrograms at the successful ablation site preceded the P-wave by 38 ± 11 (range 10-60) milliseconds, and AT termination was obtained after a mean RF energy time of 10 ± 8 (range 2-31) seconds. CONCLUSION: A characteristic narrow and biphasic (-/+) or triphasic (+/-/+) P-wave in the inferior and precordial leads reliably identifies the group of AT arising from the para-Hisian region.

Quantitative Comparison Between Amyloid Deposition Detected by (99m)Tc-Diphosphonate Imaging and Myocardial Deformation Evaluated by Strain Echocardiography in Transthyretin-Related Cardiac Amyloidosis.

BACKGROUND: Management of cardiac amyloidosis (CA) is related to amyloid deposition. Our aim was to assess the effect of amyloid deposition on myocardial function. METHODS AND RESULTS: Twenty-eight patients with transthyretin mutation and a group of 14 controls underwent echocardiography to quantify left ventricular (LV) dimensions, function, and global (G) longitudinal (L), radial (R) and circumferential (C) strain (S). (99m)Tc-3,3-diphosphono-1,2-propanodicarboxylic-acid-scintigraphy ((99m)Tc-DPD) was used to quantify CA. (99m)Tc-DPD revealed accumulation in 14/28 patients (CA group) and no accumulation (no-CA group) in 14. Cardiac accumulation was lower-than-bone uptake in 5 (mild-CA group) and higher-than-bone uptake in 9 (severe-CA group). Ejection fraction was similar among groups. GLS was lower (P<0.001) in the severe-CA group (-12.2±4.5) with respect to the no-CA group (-19.3±3.0) and to the control group (-20.9±2.5). Conversely, GCS and GRS were lower (P<0.05) in the mild-CA group (-10.8±4.1 and 9.5±5.7, respectively) with respect to the severe-CA group (-18.9±5.1 and 23.9±6.3 respectively), no-CA group (-19.2±4.1 and 28.4±10.2, respectively) and the control group (-23.9±4.4 and 29.9±8.7, respectively). A correlation was found between the scintigraphic heart retention index (HRI) and LV septal thickness (ρ=0.72), E/E' (ρ=0.46) and GLS (ρ=-0.40). CONCLUSIONS: Myocardial deformation is impaired in a different stage of CA. The (99m)Tc-DPD HRI correlated well with morphologic, diastolic and strain abnormalities. (Circ J 2016; 80: 1998-2003).

Supraventricular Tachycardia Initiated by Couplets of Atrial Extrasystoles but Not by Single Premature Atrial Beats: What Is the Mechanism?

The reported electrocardiogram shows several atrial extrasystoles (AEs) sometimes occurring in couplets. The former beat of each couplet is nonconducted, whereas the latter triggers a supraventricular tachycardia with negative P waves in inferior leads and RP > PR. This suggests an atypical atrioventricular nodal reentrant tachycardia involving the fast pathway anterogradely and the slow pathway retrogradely. The tachycardia is never precipitated by single AEs. The blocked AE of each pair is pivotal in tachycardia initiation, allowing the subsequent impulse to conduct down the fast pathway. A concealed slow pathway penetration during the blocked AE is invoked as the key mechanism.

A Case of Brugada Pattern Migrant from Right Precordial Leads to Peripheral Leads.

Since the first report in 1992, Brugada pattern (BP) diagnosis is mainly based on analysis of the precordial leads. In cases with no clear BP evidence in the conventional right precordial leads (4th intercostal space), limb leads analysis resulted helpful in suspecting BP. Fluctuations within right precordial leads between the diagnostic ECG pattern and nondiagnostic ECGs are well known. For the first time, in the patient herewith reported, the transformation of BP phenotype involves both precordial and peripheral leads, confirming that the analysis of all the 12 leads has a key role in BP diagnosis.

Impact of clinical presentation on ischaemic and bleeding outcomes in patients receiving 6- or 24-month duration of dual-antiplatelet therapy after stent implantation: a pre-specified analysis from the PRODIGY (Prolonging Dual-Antiplatelet Treatment After Grading Stent-Induced Intimal Hyperplasia) trial.

AIMS: We investigated if acute coronary syndrome (ACS) rather than stable coronary artery disease (SCAD) presentation is an outcome modifier with respect to the duration of dual-antiplatelet therapy (DAPT) in patients undergoing coronary stenting. METHODS AND RESULTS: In the Prolonging Dual-Antiplatelet Treatment After Grading Stent-Induced Intimal Hyperplasia (PRODIGY) trial, a total of 1465 (74.3%) patients presented ACS whereas 505 (25.7%) had SCAD and were randomized to 6- or 24-month DAPT. At 24 months, the composite of death, myocardial infarction (MI), or cerebrovascular accident (CVA) did not differ between the long- and short-term DAPT arms in both ACS (11.1 vs. 11.7%; P = 0.67) and SCAD (7.5 vs. 4.8%; P = 0.21) patients, respectively. Long-term DAPT was associated with a 75% increase of Bleeding Academic Research Consortium (BARC)-class 2, 3, or 5 bleeding in ACS [7.1 vs. 4.1%; hazard ratio (HR) 1.75, 95% confidence interval (CI) 1.11-2.74, P = 0.015; number needed to treat for harm (NNTH): 33.3] and a five-fold increase in SCAD (8.2 vs. 1.6%; HR 5.37, 95% CI 1.84-15.74, P = 0.002; NNTH: 15.1) patients, with a borderline quantitative interaction (PINT = 0.056). As a result, net adverse cardiovascular events (death, MI, CVA, BARC class 2, 3, or 5 bleeding) were more than doubled in SCAD patients receiving 24-month DAPT, whereas they did not differ in ACS patients (PINT = 0.024). CONCLUSIONS: This analysis suggests that clinical presentation may be a treatment modifier with respect to DAPT duration after stenting consistent with the hypothesis that SCAD-but not ACS-patients are exposed to a significant increase in bleeding and net adverse clinical events when treated with 24-month compared with 6-month therapy. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00611286. http://clinicaltrials.gov/ct2/show/NCT00611286?term=prodigy&rank=2.

An unusual narrow QRS complex tachycardia: what is the mechanism?

The electrocardiogram of a 72-year-old woman showed episodes of nonsustained narrow QRS complex tachycardia. Tracing analysis suggested that the arrhythmia was due to interpolated atrial extrasystoles occurring in bigeminal rhythm. Interpolation of atrial extrasystoles is a rare phenomenon. In this condition, a premature atrial beat is "sandwiched" between 2 normal sinus beats, and sinus PP interval containing the extrasystole is often longer than unaffected sinus cycles. Alternative mechanisms for the arrhythmia are discussed, such as: (1) sinus node reentry; (2) 1:2 response to atrial ectopy over the fast and the slow atrioventricular nodal pathways; and (3) couplets of atrial extrasystoles.

ST Segment Depression in the Inferior Leads in Brugada Pattern: A New Sign.

BACKGROUND: Brugada pattern (BP) is characterized by J wave and elevated ST segment in the right precordial leads. At times the ECG signs are present only with the electrodes displaced 1 or 2 intercostal spaces above. METHODS: We analyzed the electrocardiograms of 87 subjects with type 1 BP looking for ST segment depression (≥ 0.1 mV with duration ≥ 0.08 s) in the inferior leads. In 21 subjects, BP pattern was evident only with V1 -V2 electrodes at the 3rd or 2nd space. RESULTS: ST segment depression was present in 41 cases (47%). In the 21 patients with BP recognizable only at the 2nd or 3rd intercostal space, 10 (48%) presented a significant ST depression in the inferior leads. CONCLUSIONS: ST segment analysis in the inferior leads has never been considered for BP diagnosis. When accurately searched for, however, ST segment depression can be observed in those leads in BP, suggesting the need for further investigation.

Do patients with heart failure and right bundle branch block need biventricular pacing? A case of significant QRS narrowing by right ventricular pacing alone.

We report the case of a 56-year-old male with ischemic cardiomyopathy, severe left ventricular dysfunction and right bundle branch block (RBBB) with a wide QRS duration (180ms) who received dual-chamber implantable cardioverter-defibrillator for primary prevention of sudden death. After having placed the right ventricular lead in the middle of the inter-ventricular septum, a significant narrowing of QRS duration was observed, thus obtaining "de facto" a cardiac resynchronization therapy (CRT). This type of cardiac pacing could be an alternative to conventional CRT with left ventricular pacing in patients with wide QRS due to RBBB. The long-term effects of this RV only pacing strategy with ICD in patients with heart failure yet remain to be determined.

Age, glomerular filtration rate, ejection fraction, and the AGEF score predict contrast-induced nephropathy in patients with acute myocardial infarction undergoing primary percutaneous coronary intervention.

BACKGROUND: In patients undergoing primary percutaneous coronary interventions (PCI) for ST-segment elevation myocardial infarction (STEMI), the occurrence of Contrast-Induced Nephropathy (CIN) has a pronounced impact both on morbidity and mortality. We investigated the variables associated with CIN development in 481 consecutive patients with STEMI undergoing primary PCI and evaluated the predictive value of a 3-variable clinical risk score (the AGEF score) based on age, left ventricular ejection fraction (EF), and estimated glomerular filtration rate (eGFR). METHODS: CIN was defined as an absolute increase in serum creatinine ≥0.5 mg/dL or an increase ≥25% from baseline within 72 hr. AGEF score was calculated by adding 1 point to the Age/EF(%) ratio if the eGFR was <60 mL/min per 1.73 m(2) . RESULTS: Overall, the incidence of CIN was 5.2%. In-hospital mortality was higher in patients with CIN than in those without (16% Vs 1.3%, P = 0.001). At multivariate analysis age (OR 1.06, P = 0.042), eGFR (OR 0.95, P = 0.001), EF (OR 0.94, P = 0.007) and post-procedural TIMI flow grade (OR 0.43, P = 0.045) were independent predictors of CIN. AGEF score was an accurate (OR 5.19, P < 0.001, AUC 0.88) and calibrated (Hosmer-Lemeshow χ(2) = 10.25, P = 0.25) predictor of CIN. CONCLUSIONS: Advanced age, depressed EF, and reduced eGFR are independent predictors of CIN development after primary PCI for STEMI. The preprocedural individual patient risk can be clinically assessed with the calculation of the AGEF score, which is based on such readily available parameters.

Ventricular extrasystoles with interpolation or postponed compensatory pause during atrial fibrillation: fact or fiction?

A Holter recording obtained from a patient with atrial fibrillation showed ventricular extrasystoles often in bigeminal rhythm. Most extrasystoles were followed by a long return cycle, and only in a few instances the postextrasystolic interval was short. The latter phenomenon was interpreted as a manifestation of poor retrograde concealed penetration of the ventricular impulse into the atrioventricular (A-V) junction: accordingly, an ensuing relatively early fibrillation impulse reached the ventricular chamber, since it did not find the A-V node refractory. These events are similar to what happens in interpolated ventricular extrasystoles occurring during sinus rhythm, the absent or minimal concealed retrograde penetration of the ectopic impulse into the A-V node being necessary to permit anterograde conduction of the ensuing sinus impulse. Analysis of the recording also revealed that a very long (>2 second) interval between two consecutive narrow beats only occurred after an "interpolated" extrasystole. This was interpreted with the same mechanism underlying the "postponed compensatory pause" observed at times after interpolated ventricular extrasystoles during sinus rhythm: the minimal or nil penetration of the ventricular ectopic impulse into the A-V junction, followed by conduction of an ensuing early atrial impulse, "shifts to the right" the A-V nodal refractory period, preventing conduction of several further supraventricular impulses and generating a pause. Both interpolated ventricular extrasystoles and the phenomenon of "postponed compensatory pause" are, thus, conceivable during atrial fibrillation, although no definite demonstration is possible.

Role of 2D strain in the early identification of left ventricular dysfunction and in the risk stratification of systemic sclerosis patients.

BACKGROUND: Systemic sclerosis (SSc) is an autoimmune chronic disease characterized by diffuse fibrosis involving several organs, including heart. Aim of our study was to analyze left ventricular (LV) myocardial deformation, by use of 2D strain, in asymptomatic SSc patients with normal LV ejection fraction. METHODS: We enrolled 29 SSc patients (28 female, 65±4 years) and 30 controls (23 female, 64±2 years). Echocardiographic study with tissue Doppler imaging (TDI) and 2D strain analysis was performed; moreover, patients were submitted to a two-year follow-up for the occurrence of cardiovascular events. RESULTS: Standard echocardiographic parameters and TDI velocities were comparable between groups. LV longitudinal (LS) and circumferential (CS) strains were lower in patients than in controls (-13.1±4.8 vs -22.6±4.1, p < 0.001; -15.3±6.2 vs -20.4±5.6, p = 0.001), whereas radial strain (RS) was comparable between groups; moreover, a significant correlation of LS and CS with serum levels of Scl-70 antibodies was found (r = 0.74, p = 0.001; r = 0.53, p = 0.025). In addition, patients with cardiovascular events during follow-up showed a greater impairment of LS and CS (-10.3±2.5 vs -14.4±4.1, p = 0.015; -14.2±3.1 vs -20.1±1.6, p = 0.048) and higher values of Scl-70 antibodies serum levels (p = 0.047). CONCLUSION: The impairment of LV function, often subclinical, worsens prognosis of SSc patients, leading to increased risk of cardiovascular complications. 2D strain, allowing the early detection of LV abnormalities and the identification of patients at greater cardiovascular risk, may be a useful tool in order to provide a more accurate management of SSc patients.

Images in cardiovascular medicine: caseous calcification of the mitral annulus.

A 78-year-old woman was admitted to our emergency department for subarachnoid hemorrhage. Since a month ago, she was taking warfarin after diagnosis, on transthoracic echocardiogram (TTE), of a suspected large atrial thrombus. The patient, referred to our institution for further investigation, presented asymptomatic; electrocardiogram showed sinus rhythm. TTE revealed an echo dense spherical mass located in the mitral periannular posterior region with moderate mitral regurgitation. Transesophageal echocardiography and cardiac computed tomography confirmed a calcified round mass (2.0 × 2.9 cm) with central areas of echolucency-like liquefaction surrounded by a hyperechogenic structure without systolic flow inside the cavity. The mass was diagnosed as caseous calcification of the mitral annulus (CCMA), a rare finding associated with a benign prognosis, requiring surgery only in the presence of mitral valve dysfunction. The diagnosis of CCMA is, often, misconstrued as thrombus, tumor, or abscess, leading to unnecessary investigations or interventions. Our patient was discharged after discontinuation of warfarin.

Very late recurrence of Takotsubo syndrome.

Recurrence of the Takotsubo syndrome is possible, and in the majority of cases it occurs within 4 years. The present report is focused on a case of the Takotsubo syndrome recurrence after 10 years. The patient had been admitted for the first time in 1999 with a diagnosis of "non-q wave acute anterolateral myocardial infarction." Ten years later, she was readmitted for suspected acute myocardial infarction; coronary arteries, however, were normal, and the left ventricular angiogram demonstrated apical ballooning typical for the Takotsubo syndrome. It is worth noting that the clinical presentation and the ECG were the same on both occasions; in addition, both events were triggered by an emotional stress.

Current electrocardiographic criteria for diagnosis of Brugada pattern: a consensus report.

Brugada syndrome is an inherited heart disease without structural abnormalities that is thought to arise as a result of accelerated inactivation of Na channels and predominance of transient outward K current (I(to)) to generate a voltage gradient in the right ventricular layers. This gradient triggers ventricular tachycardia/ventricular fibrillation possibly through a phase 2 reentrant mechanism. The Brugada electrocardiographic (ECG) pattern, which can be dynamic and is sometimes concealed, being only recorded in upper precordial leads, is the hallmark of Brugada syndrome. Because of limitations of previous consensus documents describing the Brugada ECG pattern, especially in relation to the differences between types 2 and 3, a new consensus report to establish a set of new ECG criteria with higher accuracy has been considered necessary. In the new ECG criteria, only 2 ECG patterns are considered: pattern 1 identical to classic type 1 of other consensus (coved pattern) and pattern 2 that joins patterns 2 and 3 of previous consensus (saddle-back pattern). This consensus document describes the most important characteristics of 2 patterns and also the key points of differential diagnosis with different conditions that lead to Brugada-like pattern in the right precordial leads, especially right bundle-branch block, athletes, pectus excavatum, and arrhythmogenic right ventricular dysplasia/cardiomyopathy. Also discussed is the concept of Brugada phenocopies that are ECG patterns characteristic of Brugada pattern that may appear and disappear in relation with multiple causes but are not related with Brugada syndrome.

Right bundle branch block on alternate beats during acute pulmonary embolism.

The electrocardiogram of a patient with acute pulmonary embolism showed right bundle branch block (RBBB) on alternate beats; following thrombolysis, the pattern evolved to persistent RBBB and eventually to normal conduction. Analysis of serial tracings suggested that the mechanism of RBBB alternans was tachycardia-dependent bidirectional bundle branch block, caused by prolongation of both anterograde and retrograde refractory periods (RPs) of the right bundle branch (RBB). The sinus impulse found the RBB refractory, and was conducted over the left bundle branch only, depolarizing the left ventricle and then attempting to penetrate retrogradely the RBB; at that time, however, the RBB was still refractory. When a QRS complex had a RBBB configuration, therefore, the RBB was not depolarized; the ensuing sinus impulse found the RBB fully responsive as a consequence of the long period intervening between two successive depolarizations, and resulted in normal intraventricular conduction. With right ventricular afterload decrease, the recovery of RBB anterograde and retrograde excitability was asynchronous, since the retrograde RP became normal earlier than the anterograde one. In accordance with the relatively short retrograde RP, the RBB was retrogradely invaded by the transseptal impulse coming from the left ventricle; this "shifted to the right" the anterograde RP of the RBB. The RBB, thus, was still refractory to the next sinus impulse, and RBBB again occurred; the RBB, thus, was once more depolarized retrogradely, and this led to perpetuation of RBBB. Finally, intraventricular conduction became normal owing to full normalization of RBB anterograde and retrograde refractoriness.

Presumptive myocarditis with ST-Elevation myocardial infarction presentation in young males as a new syndrome. Clinical significance and long term follow up.

BACKGROUND: Acute myocarditis may mimic myocardial infarction, since affected patients complain of "typical" chest pain, the ECG changes are identical to those observed in acute coronary syndromes, and serum markers are increased. We describe a case series of presumptive myocarditis with ST segment elevation on admission ECG. METHODS AND RESULTS: From 1998 to 2009, 21 patients (20 males; age 17-42 years) were admitted with chest pain, persistent ST segment elevation, serum enzyme and troponine release. All but one patients had fever and flu-like symptoms prior to admission. No abnormal Q wave appeared in any ECG tracing, and angiography did not show significant coronary artery disease. Patients remained asymptomatic at long term follow-up, except 2 who experienced a late relapse, with the same clinical, electrocardiographic and serum findings as in the first clinical presentation. CONCLUSION: Presumptive myocarditis of possible viral origin characterized by ST elevation mimicking myocardial infarction, good short term prognosis and some risk for recurrence is relatively frequent in young males and appears as a distinct clinical condition.