Profile and Prognostic Impact of Multimorbidity in Elderly Patients with Heart Failure: Are there Differences between Men and Women?

PURPOSE OF REVIEW: Heart failure (HF) represents a pathology in constant growth, but, despite the fact that a significant proportion of its population is comprised of elderly patients, they are not adequately represented in clinical trials or registries. They constitute a heterogeneous population with their particularities and interaction of the multiple comorbidities that characterize this age group, which makes the clinical course, prognosis and outcomes of the disease different. RECENT FINDINGS: Compared to men, women with HF tend to be older, with a greater burden of non-cardiovascular comorbidities, less ischemic heart disease and preserved ventricular function in most cases. This fact translates into worse self-perceived quality of life, with lower hospitalization and mortality rates. Moreover, paradoxically, women are less likely to receive treatment recommended by clinical practice guidelines, including revascularization and device placement. As there are not enough representative studies of this population, the reasons for these results with better prognosis and relatively benign impact in the elderly female population are unknown, which is why it is necessary to continue with research in order to obtain greater evidence of the exposed gaps.

Left Atrial Peak Systolic Strain as an Indicator Pathway of Diastolic Dysfunction of the Left Ventricle.

BACKGROUND: Left atrial peak systolic strain (LA-PSS) imaging is an emerging index of left atrial function, and it was shown to be decreased in heart failure with preserved ejection fraction (EF). We aimed to determine whether LA-PSS could be used as an additional diagnostic parameter to current existing guidelines for the presence of left ventricle diastolic dysfunction (LVDD). MATERIALS AND METHODS: A total of 190 consecutive adult patients with cardiovascular risk factors and normal left ventricle EF with no prior history of heart failure were included in the study. Speckle tracking software was used to study ventricular parietal deformity, left ventricle global longitudinal systolic strain, and LA-PSS. RESULTS: The median left ventricle global longitudinal systolic strain was -19%, with a significant difference ( P < 0.001) between patients with normal diastolic function versus those with LVDD. The median LA-PSS was 33% (30% to 38%) ( P < 0.001). Most patients (61%) had grade 1 atrial dysfunction based on PSS (range 24%-35%). The analysis of the area under the receiver operating characteristic curve of the LA-PSS as a potential indicator pathway of LVDD was 67% [95% confidence interval (CI), 62-72], and 75% (95% CI, 70-80), when the indeterminate pattern was included. The decreased LA-PSS made it possible to reclassify patients with an indeterminate pattern of diastolic function in 96% of cases. CONCLUSIONS: These results support the potential role of LA-PSS as an additional parameter for the diagnosis of LVDD in patients with normal EF, and may be integrated into the guidelines for routine evaluation of patients.

ST-Segment Elevation Acute Myocardial Infarction Associated to Covid-19 Vaccination in A Healthy Young Adult with Normal Coronary Arteries.

Despite the beneficial effects of anti-COVID-19 vaccination, monitoring its safety has identified potential cardiac adverse events, mainly myocarditis and pericarditis. The case of a healthy 32-year-old male patient who developed acute myocardial infarction (AMI) 48 hours after the second dose of anti-COVID-19 mRNA vaccine (BNT162b2) is reported. This is the first reported case in the literature of an AMI associated to post-COVID-19 vaccination with mRNA vaccine (BNT162b2) in a healthy young adult without coronary risk factors and normal coronary arteries. Despite this adverse event, the continuation of the anti-COVID-19 vaccination campaign is encouraged due to the benefits it brings.

Role of the Electrocardiographic MVP Risk Score (Morphology-Voltage-P Wave Duration) in Predicting the Development of Atrial Fibrillation in Patients With Systemic Arterial Hypertension.

BACKGROUND: There is a global tendency to emphasize the prevention and early diagnosis of diseases that have a great impact on public health. Atrial fibrillation (AF) has a prevalence affecting 1.5-2% of the general population. Certain variables of the P wave allow us to identify and stratify patients at risk of developing AF. MATERIALS AND METHODS: This is an observational, descriptive, and longitudinal study to determine the applicability of the electrocardiographic (ECG) morphology, voltage, and P wave duration (MVP) risk score to predict the development of AF in consecutive patients with systemic hypertension (SH) in an initial follow-up of 12 months. RESULTS: Initially, 104 patients were included, of whom 12 died during follow-up and 17 did not attend subsequent checkups during the COVID-19 pandemic; therefore, they were excluded. The study patients were 75, of whom AF was detected in 25 patients (33%). The average duration of the P wave was 120 ± 26 ms, the average voltage was 0.1 ± 0.5 Mv. The high-risk MVP ECG score had an [area under the curve, 0.69; 95% confidence intervals (CI), 0.59-0.79] and demonstrated a specificity and a positive predictive value of 100%, a negative predictive value of 76%, and a sensitivity of 40% for predicting the development of AF. CONCLUSIONS: The present study establishes for the first time that SH patients who possess a high-risk MVP ECG score have a significantly higher incidence of developing AF. The high-risk MVP Score has a specificity and a positive predictive value of 100% and a high negative predictive value with a moderate sensitivity for the prediction of the development of AF in SH patients.

Relationship of the T-wave Tpeak-Tend interval with conduction system disorders in arterial hypertension.

PURPOSE: The Tpeak-Tend interval of the T wave has emerged as a new electrocardiographic marker of increased transmural dispersion of ventricular repolarization. We aimed to determine the presence of cardiac conduction system disorders in patients with systemic arterial hypertension (SAH) who have altered Tpeak-Tend interval of the T wave. METHODS: The 67 patients with SAH were divided into two groups. Those with prolonged (≥ 77 ms) Tpeak-Tend intervals, 21 (31%) patients were in the study group. Those with normal (< 77 ms) Tpeak-Tend intervals, 46 (69%) patients were in the control group. Alteration of ventricular repolarization manifested as a prolongation of the Tpeak-Tend interval was detected by computerized electrocardiographic analysis tools. RESULTS: The median value of QRS complex duration was significantly wider in the study group as compared to the control group (110 ± 12 ms vs. 94 ± 8 ms p < 0.001). There was a significantly greater incidence of left anterior hemiblock in the study group (14% vs. 0% p < 0.04). The median value of the QTc interval was significantly greater in the study group (440 ± 26 vs. 422 ± 15 p < 0.01). There was a significantly greater incidence of patients with prolonged QTc interval in the study group (33% vs. 11% p < 0.02). The median value of the Tpeak-Tend interval was significantly greater in the study group (84 ± 5 ms vs. 65 ± 4 ms p < 0.001), as well as, the Tpeak-Tend/QTc ratio in the study group (0.19 ± 0.1 vs. 0.16 ± 0.1 p < 0.001). CONCLUSION: There is a significantly greater ventricular repolarization disorders and abnormalities of the cardiac conduction system in SAH patients who possess altered Tpeak-Tend interval of the T wave.

OBJETIVO: El intervalo Tpico-Tfinal de la onda T es un marcador electrocardiográfico de la dispersión transmural aumentada de la repolarización ventricular. Investigamos la presencia de trastornos del sistema de conducción cardíaca en pacientes con hipertensión arterial sistémica (HA) que poseen alterado el intervalo Tpico-Tfinal de la onda T. MÉTODOS: Los 67 pacientes con HA fueron divididos en dos grupos. Aquellos con intervalos de Tpico-Tfinal prolongados (≥ 77 ms), 21 (31%) pacientes (grupo de estudio). Aquellos con intervalos normales (< 77 ms) Tpico-Tfinal, 46 (69%) pacientes (grupo control). Los intervalos Tpico-Tfinal fueron medidos por herramientas de análisis electrocardiográfico computarizado. RESULTADOS: El valor mediano de la duración del complejo QRS fue significativamente más amplio en el grupo de estudio (110 ± 12 ms vs. 94 ± 8 ms p < 0.001). Hubo una incidencia significativamente mayor de hemibloqueo anterior izquierdo en el grupo de estudio (14% vs. 0% p < 0.04). El valor mediano del intervalo QTc fue significativamente mayor en el grupo de estudio (440 ± 26 vs. 422 ± 15 p < 0.01). Hubo una incidencia significativamente mayor de pacientes con intervalo QTc prolongado en el grupo de estudio (33% vs. 11% p < 0.02). El valor mediano del intervalo Tpico-Tfinal fue significativamente mayor en el grupo de estudio (84 ± 5 ms vs. 65 ± 4 ms p < 0.001), así como el cociente Tpico-Tfinal/QTc (0.19 ± 0.1 vs. 0.16 ± 0.1 p < 0.001). CONCLUSIÓN: Existe una alteración de la repolarización ventricular significativamente mayor y anomalías del sistema de conducción cardíaca en pacientes con HA que poseen alteración del intervalo Tpico-Tfinal de la onda T.

Potential Mechanisms of Cardiac Injury and Common Pathways of Inflammation in Patients With COVID-19.

Due to the lack of prospective, randomized, controlled clinical studies on inflammation and cardiovascular involvement, the exact mechanism of cardiac injury among patients with Coronavirus Disease 2019 (COVID-19) still remains uncertain. It was demonstrated that there is a high and significantly positive linear correlation between troponin T and plasma high-sensitivity C-reactive protein levels, biomarkers of cardiac injury and systemic inflammation, respectively. Cardiac injury and inflammation is a relatively common association among patients hospitalized with COVID-19, and it is related to higher risk of in-hospital mortality. In our literature search, we identified several potential mechanisms of myocardial tissue damage, namely, coronavirus-associated acute myocarditis, angiotensin-converting enzyme 2 receptor binding affinity to the virus Spike protein, increased cytokine secretion, and hypoxia-induced cardiac myocyte apoptosis. Elucidation of the disease pathogenesis and prospective histopathological studies are crucial for future proper treatment in case of renewed outbreaks. Of interest is that with hundred of thousands of bodies available for autopsy studies, no prospective investigation has been reported so far. Strong efforts and continued research of the cardiovascular complications and identification of risk factors for poor prognosis in COVID-19 are steadily needed. The high morbidity and mortality of COVID-19, its monumental economic burden and social impact, the despair of a new pandemic outbreak, and the thread of potential utilization of novel severe acute respiratory syndrome coronavirus 2 as biologic weapons make it a preponderant necessity to better comprehend the therapeutic management of this lethal disease. Emerging as an acute infectious disease, COVID-19 may become a chronic epidemic because of genetic recombination. Therefore, we should be ready for the reemergence of COVID-19 or other coronaviruses.

The relation between QRS complex fragmentation and segmental abnormalities of the myocardial contractility in patients with coronary artery disease.

BACKGROUND: Fragmented QRS (fQRS) is defined as any QRS complex with duration of less than 120 ms (ms) and at least one notch in the R or S wave in two or more leads belonging to the same coronary territory. The fQRS represents a delay in ventricular conduction caused by a myocardial scar associated to arrhythmic events. METHODS: This is a descriptive, retrospective, cross-sectional study of a total of 123 patientsadmitted with ischemic heart disease. The aim was to correlate the presence of fQRS in a conventional 12-leads electrocardiogram (ECG) with myocardial regional motility disorders. RESULTS: A total of 62% of the patients were male, the mean age was 63 ± 12 SD. fQRS was observed in 44% (64% men and 36% women), the most frequent location being the inferior wall (61%), followed by the anteroseptal and lateral walls (14% for both). Of the 36 patients with fQRS, 30 had segmental disorders, while 6 did not. Of the 45 patients without fQRS, 28 had segmental disorders, but 17 did not, which gives us a sensitivity of 52% (moderate SnNout) and specificity of 74% (high SpPin), with a positive predictive value of 83%, a negative predictive value of 38% and a prevalence of 72%. CONCLUSION: The presence of fQRS in the ECG has high specificity and a high positive predictive value of the existence of segmental myocardial motility disorders in patients with documented coronary artery disease.

Paroxysmal Atrial Fibrillation of Vagal Mechanism with Episodes of Wide QRS Complex Tachycardia Due to Gouaux-Ashman's Phenomenon.

A 38-year-old male patient consulted for nocturnal palpitations described as fast chest pounding that woke him up from sleep. A physical examination yielded no remarkable findings. A 24-hour Holter ECG monitoring demonstrated nocturnal episodes of paroxysmal atrial fibrillation (PAF) with the coexistence of wide QRS complex tachycardia. To the best of our knowledge, this is the first reported case of nocturnal episodes of wide QRS complex tachycardia during vagally mediated PAF resulting from Gouaux-Ashman's phenomenon. It is paramount for general physicians to recognize this phenomenon because it should be differentiated from ventricular tachycardia, since prognosis and treatment of both entities are entirely different. General and emergency physicians should be aware in order to improve adequate diagnostic and therapeutic management of the arrhythmic episodes.

Identificación de Factores Clínicos Relacionados a una Mayor Mortalidad Asociada a Insuficiencia Renal Aguda en pacientes de Terapia Intensiva

La insuficiencia renal aguda (IRA) es una de las complicaciones más frecuentes en los pacientes hospitalizados, siendo un factor de riesgo de mortalidad. Es de suma importancia identificar la asociación de factores clínicos que empeoran la mortalidad en pacientes con IRA internados en una unidad de terapia intensiva (UTI). Se incluyeron 218 pacientes, de los cuales el 63,7% (n=139) correspondieron a hombres con un promedio de edad de 43±19 años. El análisis de correlación de variables de control, dependiente e independiente fue a través del coeficiente de Spearman y el OR fue analizado mediante regresión logística. De los 218 pacientes, falleció el 33% (n=72) de los pacientes internados en UTI. La IRA ocurrió en 28,4% (n=62) del total de pacientes y de estos, el 61,3% (n=38) fallecieron, con un OR de 4,94 (p 0,0001). La mayor proporción de fallecidos perteneció a la categoría AKIN 3. Las variables clínicas de ventilación mecánica (PR 3,57, IC 95%, 0,34-37,93), uso de drogas vasoactivas (PR 8,32, IC 95%, 3,20-21,64), puntuación APACHE III (PR 1,12, IC 95%, 1,03-1,23), edad (PR 1,01, IC 95%, 0,99-1,04) y los sometidos a cirugía (PR 0,28, IC 95%, 0,10-0,80) tuvieron asociación positiva y aumentaron la mortalidad. La presencia de variables clínicas de ventilación mecánica, la utilización de drogas vasoactivas, sepsis, el estudio APACHE III, la edad, la categoría AKIN 3, y el antecedente de cirugía previo al ingreso a UTI aumentan significativamente la mortalidad en pacientes con IRA en UTI.

Acute renal failure (ARF) is one of the most frequent complications in hospitalized patients and is a risk factor for mortality. It is extremely important to identify the association of clinical factors that worsen mortality in patients with ARF admitted to an intensive care unit (ICU). A total of 218 patients were included, of which 63.7% (n=139) were men with a mean age of 43±19 years. The correlation analysis of control, dependent, and independent variables was done through Spearman's coefficient and the OR was analyzed through logistic regression. Of the 218 patients, 33% (n=72) died in the ICU. ARF occurred in 28.4% (n=62) of all patients and of these, 61.3% (n=38) died, with an OR of 4.94 (p 0.0001). The highest proportion of deceased patients were in the AKIN 3 category. The clinical variables of mechanical ventilation (PR 3.57, 95% CI, 0.34-37.93), use of vasoactive drugs (PR 8.32, 95% CI, 3.20-21.64), APACHE III score (PR 1.12, 95% CI, 1.03-1.23), age (PR 1.01, 95% CI, 0.99-1.04) and those who underwent surgery (PR 0.28, 95% CI, 0.10-0.80) had a positive association and increased mortality. The presence of clinical variables of mechanical ventilation, the use of vasoactive drugs, sepsis, APACHE III stage, age, AKIN 3 category, and a history of surgery before admission to the ICU significantly increase mortality in patients with ARF in ICU.

Ablación por cateter de radiofrecuencia de extrasístoles ventriculares con origen en el seno coronario izquierdo

Las extrasístoles ventriculares (EEVV) son frecuentemente asintomáticas y no requieren de tratamiento antiarrítmico. Las EEVV de los tractos de salida son las EEVV idiopáticas más frecuentes en la práctica clínica. La anamnésis, el examen físico y el electrocardiograma son fundamentales en el diagnóstico. Aunque las EEVV de los tractos de salidas ventriculares son consideradas benignas, pueden producir diversos síntomas y desencadenar una cardiomiopatía inducida por las extrasístoles, que lleva a un deterioro de la función sistólica ventricular izquierda y en última instancia, insuficiencia cardiaca. Cuando el tratamiento farmacológico de las EEVV fracasa, nos queda la ablación de arritmias por catéter de radiofrecuencia como única alternativa eficaz. Este es el caso de la paciente de sexo femenino de 62 años, hipertensa, dislipidémica y tabaquista, que demuestra la seguridad de la ablación por catéter de radiofrecuencia, la eficacia terapéutica, y el restablecimiento integro de la función ventricular del corazón.

Premature ventricular complexes (PVC) are frequently asymptomatic and do not require antiarrhythmic treatment. Outflow tract PVC are the most common idiopathic PVC in clinical practice. The anamnesis, physical examination and electrocardiogram are essential in the diagnosis of these patients. Although PVC of the ventricular outflow tracts are considered benign, they can produce various symptoms such as dyspnea on exertion, asthenia, palpitations, dizziness, presyncope or syncope, and in those patients with very high arrhythmic burden (>24% on a 24-hour Holter monitoring), can trigger extrasystole-induced cardiomyopathy, leading to deterioration of left ventricular systolic function and ultimately heart failure. When pharmacological treatment of PVC fails, ablation of arrhythmias by radiofrequency catheter is the only effective alternative. This is the case of the 62-year-old female patient, hypertensive, dyslipidemic and a smoker, which demonstrates the safety of radiofrequency catheter ablation, the therapeutic efficacy, and the complete restoration of the ventricular function of the heart.

Myocardial Fibrosis as a Pathway of Prediction of Ventricular Arrhythmias and Sudden Cardiac Death in Patients With Nonischemic Dilated Cardiomyopathy.

The mechanism of sudden cardiac death (SCD) in patients with nonischemic dilated cardiomyopathy (NIDCM) is mostly due to sustained ventricular tachycardia and ventricular fibrillation. The clinical guidelines for the therapeutic management of this set of patients are mostly based on left ventricular ejection fraction value which has a low specificity to differentiate the risk of SCD from the risk of mortality associated with heart failure or other comorbidities. Moreover, since SCD can occur in patients with normal or mildly depressed ejection fraction, it is necessary to identify new markers to improve the prognostic stratification of SCD. Several studies that analyzed the ventricular arrhythmia substrate found that myocardial fibrosis plays an important role in the genesis of ventricular arrhythmias in patients with NIDCM. The surrounding zone of the area of fibrosis is a heterogeneous medium, where tissue with different levels of fibrosis coexists, resulting in both viable and nonviable myocardium. This myocardial fibrosis may constitute a substrate for ventricular arrhythmias, where slow and heterogeneous conduction may favor the genesis of reentry mechanism increasing the chance to develop sustained ventricular tachycardia or ventricular fibrillation. Therefore, the evaluation of ventricular fibrosis by late gadolinium enhancement (LGE) cardiac magnetic resonance imaging has been suggested as an indicator for SCD risk stratification. Indeed, LGE in patients with NIDCM is associated with increased risk of all-cause mortality, heart failure hospitalization, and SCD. Detection of myocardial fibrosis as LGE by cardiac magnetic resonance imaging can be considered as a useful pathway of prediction of malignant ventricular arrhythmias since it has excellent prognostic characteristics and may help guide risk stratification and management in patients with NIDCM.

The Association Between Atrial Fibrillation and Endurance Physical Activity: How Much is too Much?

Atrial fibrillation (AF) is the most common arrhythmia in middle-aged athletes. Physical exercise performed in a regular basis has been shown to be beneficial for cardiovascular health. Moderate physical exercise, aside from producing a nice, peaceful and well-being sensation, has been associated with a reduced risk of AF. However, more strenuous endurance exercise, like the one experiencing marathon runners, seems to increase the risk of AF in healthy athletes without organic heart disease. On the other hand, low physical activity was found to be a risk factor for the appearance of AF. Nevertheless, the relationship of exercise to AF is complex, influenced by the intensity and the duration of the physical activity, and seems to have a U-shaped relationship with the greatest levels of physical activity possibly increasing AF incidence. There is cumulative data associating moderate physical activity to reduced AF incidence, hence physicians should recommend moderate exercise training to patients with AF. This may not only reduce AF risk, but would also contribute to an overall cardiovascular benefit. However, since there is also important data suggesting significant increased incidence of AF in elite athletes with long-term endurance physical activity, it may be a serious concern to go to the extreme. In most things in life it is much better and wiser to be well balanced, always in equilibrium.

Doble tormenta tiroidea y arrítmica en una gestante con múltiples taquicardias refractarias mediadas por un haz de kent intermitente ablacionado exitosamente

La tormenta tiroidea es un estado crítico y poco frecuente que condiciona la disfunción de múltiples órganos por el efecto del exceso de las hormonas tiroideas, esta disfunción endócrina tiene una elevada mortalidad y genera manifestaciones típicas como la taquicardia, fiebre, alteraciones gastrointestinales, cardiovasculares y del sistema nervioso central. El embarazo se ha asociado con un incremento en la incidencia de arritmias. Necesitan un tratamiento inmediato con drogas antiarrítmicas, cardioversión eléctrica o cesárea de urgencia. El WPW es una anormalidad cardiaca congénita que consiste en la presencia de un haz anómalo (Haz de Kent) que evita el sistema normal de conducción uniendo directamente aurículas y ventrículos. Veremos el caso de una gestante de 32 semanas que presenta un cuadro de tormenta tiroidea y múltiples episodios de taquicardia paroxística supraventricular (TPS), de tórpida y sombría evolución clínica mediada por un haz anómalo de Kent intermitente. Es evidente que la tormenta tiroidea en el contexto de la gestación produjo cambios en las propiedades electrofisiológicas del haz anómalo de Kent intermitente lo cual propició el desarrollo de múltiples taquicardias paroxísticas supraventriculares refractarias a la cardioversión eléctrica y farmacológica. Tampoco mejoró con la tiroidectomía total, solamente cedió por completo con la ablación por catéter de radiofrecuencia del haz anómalo de Kent.

Thyroid storm is a critical and infrequent state that conditions the dysfunction of multiple organs due to the effect of excess thyroid hormones. This endocrine dysfunction has a high mortality and generates typical manifestations such as tachycardia, fever, gastrointestinal, cardiovascular and heart disorders, and the central nervous system. Pregnancy has been associated with an increased incidence of arrhythmias. They need immediate treatment with antiarrhythmic drugs, electrical cardioversion, or emergency caesarean section. WPW is a congenital cardiac abnormality that consists of the presence of an abnormal bundle (Kent bundle) that prevents the normal conduction system, directly joining the atria and ventricles. We will see the case of a 32-week pregnant woman who presented symptoms of thyroid storm and multiple episodes of paroxysmal supraventricular tachycardia (PST), with a torpid clinical course mediated by an abnormal intermittent Kent bundle. It is evident that the thyroid storm in the context of pregnancy produced changes in the electrophysiological properties of the intermittent Kent bundle, which led to the development of multiple PST refractory to electrical and pharmacological cardioversion. Moreover, it also did not improve with total thyroidectomy, only resolved completely with radiofrequency catheter ablation of the Kent bundle.

Mechanisms for the genesis of paroxysmal atrial fibrillation in the Wolff Parkinson-White syndrome: intrinsic atrial muscle vulnerability vs. electrophysiological properties of the accessory pathway.

BACKGROUND: Paroxysmal atrial fibrillation (PAF) develops in up to one-third of patients with the Wolff Parkinson-White syndrome (WPW). The reason for this high incidence of PAF in the WPW syndrome is not yet clearly understood. When PAF appears in patients with WPW syndrome who have anterograde conduction via the accessory pathway (AP), it may be life-threatening if an extremely rapid ventricular response develops degenerating into ventricular fibrillation. METHODS AND RESULTS: Several mechanisms responsible for the genesis of PAF in WPW patients were hypothesized, namely, spontaneous degeneration of atrioventricular reciprocating tachycardia into atrial fibrillation (AF), electrical properties of the APs, effects of APs on atrial architecture, and intrinsic atrial muscle vulnerability. Focal activity, multiple reentrant wavelets, and macroreentry have all been implicated in AF, perhaps under the further influence of the autonomic nervous system. AF can also be initiated by ectopic beats originating from the pulmonary veins, and elsewhere. Several studies demonstrated a decrease incidence of PAF after successful elimination of the AP, suggesting that the AP itself may play an important role in the initiation of PAF. However, PAF still occurs in some patients with the WPW syndrome even after successful elimination of the AP. There is an important evidence of an underlying atrial disease in patients with the WPW syndrome. CONCLUSIONS: Atrial vulnerability has been studied performing an atrial endocardial catheter mapping and analysing abnormal atrial electrograms. Other studies evaluated atrial refractoriness and intraatrial conduction times, suggesting an intrinsic atrial vulnerability as the mechanism of PAF and considering the AP as an innocent bystander. It is our intention to analyse the available data on this particular and interesting topic since AF has a singular prognostic significance in patients with the WPW syndrome, and its incidence is unusually high in the absence of any clinical evidence of cardiac organic disease.

Fisiopatología del bloqueo interauricular y su rol como predictor de arritmias supraventriculares

El Bloqueo Interauricular (BIA) puede servir como un valioso marcador electrocardiográfico para evaluar el riesgo del desarrollo de arritmias auriculares, y nueva aparición de fibrilación auricular (FA). El BIA se produce por un deterioro en la conducción auricular que implica un retraso en la conducción del estímulo eléctrico desde la aurícula derecha a la aurícula izquierda. Las causas probables de interrupción del haz de Bachmann incluyen isquemia, enfermedad degenerativa del envejecimiento, enfermedades infiltrativas, enfermedad coronaria difusa y afecciones inflamatorias. Los factores de riesgo para el BIA avanzado, la fibrilación auricular (FA) y el accidente cerebrovascular (ACV) parecen ser muy similares, y la patogénesis subyacente probablemente se deba a fibrosis miocárdica y remodelación auricular. El bloqueo interauricular se relaciona clínicamente a la aparición de taquiarritmias supraventriculares y está relacionado al remodelamiento auricular. Aunque el agrandamiento auricular y el BIA comparten un patrón electrocardiográfico similar, son dos entidades separadas. Sin embargo, muchos autores aún asocian una duración de la onda P mayor a 120 ms con agrandamiento de la aurícula izquierda. El remodelamiento auricular modifica la velocidad de conducción, la arquitectura cardiaca, los canales iónicos dependientes de voltaje, y los componentes de resistencia y capacitancia, como son el espacio extracelular y las uniones celulares. La alteración de estas propiedades afecta las propiedades electrofisiológicas de la conducción auricular y favorece el BIA, los trastornos auriculares y la génesis de FA.

Interatrial block (IAB) can serve as a valuable electrocardiographic marker to assess the risk of developing atrial arrhythmias, and new onset of atrial fibrillation (AF). The IAB is produced by a deterioration in atrial conduction that implies a delay in the conduction of the electrical stimulus from the right atrium to the left atrium. Probable causes of Bachmann bundle interruption include ischemia, degenerative disease of aging, infiltrative diseases, diffuse coronary disease, and inflammatory conditions. The risk factors for advanced IAB, atrial fibrillation (AF), and cerebrovascular accident (CVA) appear to be very similar, and the underlying pathogenesis is probably due to myocardial fibrosis, and atrial remodeling. The interatrial block is clinically related to the appearance of supraventricular tachyarrhythmias and is related to atrial remodeling. Although atrial enlargement and IAB share a similar electrocardiographic pattern, they are separate entities. However, many authors still associate P wave duration greater than 120 ms with left atrial enlargement. Atrial remodeling modifies conduction velocity, cardiac architecture, voltage-gated ion channels, and resistance and capacitance components, such as the extracellular space and cell junctions. The alteration of these properties affects the electrophysiological properties of atrial conduction and favors IAB, atrial disorders, and the genesis of AF.

Atrioventricular Nodal Catheter Ablation in Atrial Fibrillation Complicating Congestive Heart Failure.

The development of atrial fibrillation (AF) during the course of the evolution of heart failure (HF) worsens the clinical outcomes and the prognosis accounting for an enormous economic burden on healthcare. AF is considered to be an independent predictor of morbidity and mortality increasing the risk of death and hospitalization in 76% in HF patients. Despite the good clinical results obtained with conventional pharmacological agents and different new drugs, the optimal medical treatment can fail in the intention to improve symptoms and quality of life of HF patients with severe left ventricular dysfunction and AF with uncontrolled ventricular rate. Therefore, the necessity to utilize cardiac devices to perform cardiac resynchronization therapy (CRT), or the need to use catheter ablation, or both, emerges facing the failure of optimal medical treatment in order to achieve hemodynamic improvement. Some of these AF patients will require atrio-ventricular nodal (AVN) catheter ablation in order to restore 100% CRT functionality and improvements in clinical outcomes. It is hard to imagine that the deliberate destruction of a natural and normally functional specialized tissue of the main conduction system of the heart would do any good. However, in the presence of AF with rapid ventricular response due to normal conduction through the AV node in HF patients, the fast ventricular rate can cause deleterious consequences in the clinical outcome. Moreover, there are interesting published data which will be analyzed in this manuscript documenting significant acute and long-term improvement in left ventricular function, symptoms, exercise tolerance, clinical outcomes, and quality of life in selected HF patients with paroxysmal and persistent drug-refractory AF who have undergone AVN ablation and permanent pacemaker implantation.

Relationship of the T-wave Tpeak-Tend interval with conduction system disorders in arterial hypertension / Relación del intervalo Tpico-Tfinal de la onda T con trastornos del sistema de conducción en hipertensión arterial

Abstract Purpose: The Tpeak-Tend interval of the T wave has emerged as a new electrocardiographic marker of increased transmural dispersion of ventricular repolarization. We aimed to determine the presence of cardiac conduction system disorders in patients with systemic arterial hypertension (SAH) who have altered Tpeak-Tend interval of the T wave. Methods: The 67 patients with SAH were divided into two groups. Those with prolonged (≥ 77 ms) Tpeak-Tend intervals, 21 (31%) patients were in the study group. Those with normal (< 77 ms) Tpeak-Tend intervals, 46 (69%) patients were in the control group. Alteration of ventricular repolarization manifested as a prolongation of the Tpeak-Tend interval was detected by computerized electrocardiographic analysis tools. Results: The median value of QRS complex duration was significantly wider in the study group as compared to the control group (110 ± 12 ms vs. 94 ± 8 ms p < 0.001). There was a significantly greater incidence of left anterior hemiblock in the study group (14% vs. 0% p < 0.04). The median value of the QTc interval was significantly greater in the study group (440 ± 26 vs. 422 ± 15 p < 0.01). There was a significantly greater incidence of patients with prolonged QTc interval in the study group (33% vs. 11% p < 0.02). The median value of the Tpeak-Tend interval was significantly greater in the study group (84 ± 5 ms vs. 65 ± 4 ms p < 0.001), as well as, the Tpeak-Tend/QTc ratio in the study group (0.19 ± 0.1 vs. 0.16 ± 0.1 p < 0.001). Conclusion: There is a significantly greater ventricular repolarization disorders and abnormalities of the cardiac conduction system in SAH patients who possess altered Tpeak-Tend interval of the T wave.

Resumen Objetivo: El intervalo Tpico-Tfinal de la onda T es un marcador electrocardiográfico de la dispersión transmural aumentada de la repolarización ventricular. Investigamos la presencia de trastornos del sistema de conducción cardíaca en pacientes con hipertensión arterial sistémica (HA) que poseen alterado el intervalo Tpico-Tfinal de la onda T. Métodos: Los 67 pacientes con HA fueron divididos en dos grupos. Aquellos con intervalos de Tpico-Tfinal prolongados (≥ 77 ms), 21 (31%) pacientes (grupo de estudio). Aquellos con intervalos normales (< 77 ms) Tpico-Tfinal, 46 (69%) pacientes (grupo control). Los intervalos Tpico-Tfinal fueron medidos por herramientas de análisis electrocardiográfico computarizado. Resultados: El valor mediano de la duración del complejo QRS fue significativamente más amplio en el grupo de estudio (110 ± 12 ms vs. 94 ± 8 ms p < 0.001). Hubo una incidencia significativamente mayor de hemibloqueo anterior izquierdo en el grupo de estudio (14% vs. 0% p < 0.04). El valor mediano del intervalo QTc fue significativamente mayor en el grupo de estudio (440 ± 26 vs. 422 ± 15 p < 0.01). Hubo una incidencia significativamente mayor de pacientes con intervalo QTc prolongado en el grupo de estudio (33% vs. 11% p < 0.02). El valor mediano del intervalo Tpico-Tfinal fue significativamente mayor en el grupo de estudio (84 ± 5 ms vs. 65 ± 4 ms p < 0.001), así como el cociente Tpico-Tfinal/QTc (0.19 ± 0.1 vs. 0.16 ± 0.1 p < 0.001). Conclusión: Existe una alteración de la repolarización ventricular significativamente mayor y anomalías del sistema de conducción cardíaca en pacientes con HA que poseen alteración del intervalo Tpico-Tfinal de la onda T.

The open artery hypothesis: beneficial effects and long-term prognostic importance of patency of the infarct-related coronary artery.

There seem to be additional mechanisms of benefit in patients receiving late reperfusion therapy in a time when the opportunity for myocardial salvage has been missed. Previous studies have demonstrated that the restoration of blood flow in the infarct-related coronary artery in patients with acute myocardial infarction improves left ventricular function and reduces mortality. Initially, it was thought that survival was improved because viable myocardium was salvaged. However, data obtained over the past several years have suggested that the restoration of antegrade flow in the infarct-related artery may improve survival via a mechanism independent of the influence on left ventricular function. Clinical interest in the open artery hypothesis has recently resurfaced owing to a substantial improvement in technical aspects of percutaneous coronary interventions (PCI). Observational data suggest a role for late intervention as safer and more effective mechanical reperfusion practices have emerged. Long-term clinical benefits have been shown from balloon angioplasty late after myocardial infarction (MI). Therefore, patients with failed thrombolysis or those with late-presenting MI may still benefit from PCI by mechanisms independent of myocardial salvage. There is accumulative evidence on this matter. Possible mechanisms include reduction of ventricular remodeling, diminished ventricular instability reducing the incidence of arrhythmias, and provision of collaterals to other territories in the event of further coronary artery occlusion. However, caution must be exercised in interpreting the results of studies examining the open artery hypothesis. This hypothesis can be tested in its purest sense in animal experiments; however, the clinical situation is much more complex. Patients may have acute-on-chronic coronary artery occlusion in the presence of multivessel disease and well-developed collateral channels. The pattern of necrosis may also be different with areas of necrosis separated by islands of ischemic, stunned, hibernating, or normal cells. Therefore, the patency of the infarct-related coronary artery in single or multivessel disease days to weeks after infarction markedly influences long-term prognosis unrelated to improvement of left ventricular function. Current technology has made it feasible to open and maintain patency of most occluded infarct-related arteries. However, the hypothesis that late mechanical reperfusion in patients with asymptomatic occluded infarct-related artery will improve long-term clinical outcomes remains to be proved and is currently being tested in a large randomized trial.