International Normalized Ratio Variability: A Measure of Anticoagulation Quality or a Powerful Mortality Predictor.

BACKGROUND: As atrial fibrillation (AF) carries twice the mortality hazard when compared with a similar population without diagnosed AF, the importance of risk stratifying is obvious. Several variables are related to outcome: age, comorbidities, and use of several medications, particularly oral anticoagulants. The CHA2DS2VASc score is an extremely useful tool to predict thromboembolic events and also mortality. The international normalized ratio (INR) variability is a treatment efficacy variable also associated with morbidity in patients receiving warfarin. The objective of the study is to compare the prognostic value of the CHA2DS2VASc versus the INR variability or its combination to predict mortality. METHODS: In this observational study, we analyzed 589 patients from our Atrial Fibrillation Cohort, all on warfarin for more than 1 year and had more than 5 INRs performed in the last 2 years. The CHA2DS2VASc, HAS-BLED, and SAMe-TT2R2 scores were calculated as well as the INR variability using the time-in-therapeutic-range (TTR), the percentage of INRs (%INRs) within range, and the standard deviation of the INRs (SDINRs). Kaplan-Meier survival curves were plotted via different cutoff points. RESULTS: The mean TTR was 53 ± 23%; 34.6% of the patients had a TTR above 64%. The mean %INRs in range was 50.2 ± 20.2; 17.3% of the population had %INRs in range above 70%. The mean SDINRs was .84 ± .54, and 38.4% had SDINRs below .79. Of 598, 139 (22%) discontinued warfarin treatment. Death was responsible for almost 50% of treatment discontinuation. Of 598, 68 patients died during the study period (11.5 %); the most frequent causes of death were heart failure (30%), bleeding (17%), and ischemic stroke (15%). Patient survival had a correlation with TTR, %INRs in range, SDINRs, left ventricular ejection fraction, CHA2DS2VASc, and the combination of CHA2DS2VASc + SDINRs (cutoff >1 and >.79, respectively). CONCLUSIONS: INR variability is an extremely useful tool to assess anticoagulation quality. Calculation of both CHA2DS2VASc and INR variability appears to be extremely useful to predict mortality in patients with AF receiving warfarin. The SDINRs emerges as a strong mortality predictor compared to the other INR variability indexes.

Mortality in patients on renal replacement therapy and permanent cardiac pacemakers.

End stage renal disease is a relatively frequent disease with high mortality due to cardiac causes. Permanent pacemaker (PM) implantation rates are also very common; thus combination of both conditions is not unusual. We hypothesized that patients with chronic kidney disease with a PM would have significantly higher mortality rates compared with end stage renal disease patients without PM. Our objectives were to analyze mortality of patients on renal replacement therapy with PM. 2778 patients were on renal replacement therapy (RRT) and 110 had a PM implanted during the study period. To reduce the confounding effects of covariates, a propensity-matched score was performed. 52 PM patients and 208 non-PM matched patients were compared. 41% of the PM were implanted before entering the RRT program and 59% while on RRT. Mortality was higher in the PM group. Cardiovascular disease and infections were the most frequent causes of death. Propensity analysis showed no differences in long-term mortality between groups. We concluded that in patients on RRT and PM mortality rates are higher. Survival curves did not differ from a RRT propensity-matched group. We concluded that the presence of a PM is not an independent mortality risk factor in RRT patients.

Dabigatran and left atrial appendage thrombus.

A 59-year-old white woman with previous history of arterial hypertension consulted because of palpitations. Atrial fibrillation of uncertain duration was diagnosed. She was not receiving anticoagulants. A trans-esophageal echocardiogram was performed, and a large left atrial appendage thrombus was detected. A strategy of rate control and anti-vitamin K treatment was started. On the subsequent days, we could not reach therapeutic INRs. Therefore, it was decided to stop warfarin and initiate dabigatran. We describe the evolution of the patient, the thrombus resolution, and a successful electrical cardioversion. In our comments, we summarize the natural history of left atrial thrombus, both with and without anticoagulant therapy. We also discuss the differences between warfarin and dabigatran.

Syncope caused by huge hiatal hernia.

A 84-year-old white female had a brief loss of consciousness while playing bridge. A few minutes before the episode she had eaten pizza and significant amount of carbonated soft drinks. After recovery, her friends noticed that she was alert, but pale and sweating. Upon arrival at the emergency room, sitting blood pressure was 160/60 mmHg with a normal sinus rhythm. A chest X-Ray was performed, which was essential to make the diagnosis. The X-Ray showed a large retrocardiac opacity with air and liquid level compatible with a giant hiatus hernia. After a copious snack the hiatal hernia compressed the left atrium, decreasing the left cardiac output, elucidating the mechanism of the syncopal episode. In patients presenting with swallow syncope (particularly after a copious meal, validating the importance of a careful history), a chest X-Ray should be always be performed.

Wide complex irregularly regular tachycardia with QRS alternation.

A 44-year-old white man was referred to our service because of a history of symptomatic rapid palpitations that had begun on January 2007. He had no previous history of syncope or family history of sudden cardiac death. The patient was otherwise well and had not been taking any medications. The electrocardiogram (ECG) recorded during sinus rhythm was within normal limits. A 12-lead ECG was performed during the last episode on July 2007 while he was working at his office. An irregular wide complex tachycardia with varying QRS morphology (left bundle-branch block with an alternating pattern) was documented. The differential diagnoses based on the 12-lead electrocardiogram (ECG) were supraventricular tachycardia with aberrant conduction and QRS alternans, atrial tachycardia with anterograde conduction over an accessory pathway, or ventricular tachycardia. An electrophysiology study was performed and the results are discussed.

Medium- and long-term survival after pacemaker implant: Improved survival with right ventricular outflow tract pacing.

INTRODUCTION: Long-term prognosis after pacemaker implant depends on numerous variables, particularly structural heart disease. There is evidence that apical stimulation could favor the development of heart failure and, therefore, influence mortality. Other right ventricular pacing sites have been studied, for example the outflow tract, but no reports regarding long-term clinical outcome are available. OBJECTIVE: Compare all-cause mortality between two different sites of stimulation in the right ventricle. METHODS: We retrospectively analyzed 150 consecutive patients who underwent pacemaker implantation because of complete AV block (spontaneous or after AV node ablation), symptomatic second-degree AV block, and symptomatic atrial fibrillation with slow ventricular response. All patients were implanted at the same institution with the standard technique. Apical stimulation was performed with a passive or active fixation lead and outflow tract pacing with an active fixation lead. Data collection period began in July 1999 and ended on December 2004. All patients included were greater than 70% ventricular paced during pacemaker follow-up. Patients older than 85 years were excluded from the analysis. Age, pacemaker mode, sex, ejection fraction, diabetes, and structural cardiac disease were analyzed. Mean age was 72+/-7 years (median 74 years, range 27-85 years), 101 (67%) were male, 56 had implanted a VVI PM, and 94 patients a DDD PM. Patients were divided into two groups: outflow tract (55 patients) and apical pacing (95 patients). Mean follow-up was 1,231+/-642 days (median 1,158 days, range 9 to 2,694 days), which ended on July 2007. Total mortality was examined with the Kaplan-Meier method to construct overall survival curves. Multivariate Cox proportional hazards regression models were performed. RESULTS: All patients or relatives were contacted personally or by phone. There were no major statistical differences in patient background between the two groups. During follow-up, 18 patients (32%) died in the outflow tract group and 49 (51%) in the apical group (log-rank p=0.02). Cox regression multivariate analysis showed that outflow tract pacing and a low left ventricular ejection fraction (<40%) were the only independent variables with significant correlation with survival (p=0.006 and 0.003, respectively). CONCLUSIONS: Outflow tract pacing appears to improve medium- and long-term survival. Prospective randomized trials with a greater amount of patients are necessary to confirm the findings of this study.

Tremor as a cause of pseudoatrial flutter.

Muscle tremors mimicking atrial or ventricular arrhythmias are unusual. If present, however, misdiagnosis and consequently inappropriate treatments are possible. The authors present a patient with Parkinson's disease who was referred for evaluation of the need for oral anticoagulation because of persistent atrial flutter.

Interferencias electromagnéticas en pacientes con marcapasos y cardiodesfibriladores implantados / Electromagentic interfenrebce in patients with pacemaker and implanted cardiodesfibrillator

Hemos efectuado una revisión de las probables interferencias electromagnéticas en aquellos pacientes portadores de marcapasos cardíacos (MP) o cardiodesfibriladores automáticos implantables (DAI), o ambos, tanto en la vida diaria como en el ambiente laboral, y también cuando son sometidos a una serie de exámenes y procedimientos terapéuticos en un ambiente médico. Dada la gran cantidad de señales electromagnéticas que nos rodean, los probables problemas son mínimos, pudiéndose aún disminuirlos en un mayor rango con una correcta educación del paciente y de los médicos no habituados al manejo de pacientes portadores de estos sistemas. Un trabajo en conjunto, con pautas claras, entre los cardiólogos electrofisiólogos o marcapasistas y los demás colegas de disciplinas diferentes, redundaría en un beneficio para el paciente, disminuyendo el mínimo los problemas que las interferencias electromagnéticas puedan causar en estos pacientes.

Atrioventricular block during upright tilt table test.

Patients with a cardioinhibitory response (asystole or atrioventricular block [AVB]) during upright tilt table test (UTT) constitute a therapeutic challenge. Our present knowledge is partial and in those who experience AVB is absent. Furthermore, we ignore if there is any difference between both groups, particularly pacemaker indication. We aimed to study patients with a cardioinhibitory response during UTT and incidence of AVB during UTT, compared to asystole; plus the outcome during prolonged follow-up. Of 867 patients who underwent UTT, 172 were positive for a neurally mediated response, all with normal neurocardiovascular evaluation. Of the 172 patients, 6 (3.4%) developed AV block (group A), and 26 (15.1%) experienced asystole (group B). Group A included 6 women (100%), mean age 21 +/- 12 years. All patients in group A had sinus rate deceleration during AVB. Group B included 10 women (38%), mean age 28 +/- 17 years, and a mean pause of 15 +/- 9 seconds. We contacted 30 of 32 patients, mean follow-up of 45 +/- 38 months. Seven patients in group B had syncopal recurrences; five had 2 or more episodes. One patient from group B received a DDD pacemaker. In group A, one had one recurrence. No deaths were observed. AVB during UTT is rare, occurs in young women, and is always associated with sinus rate deceleration. Medium- to long-term prognosis is good, and equivalent to patients with asystole. There is no evidence that patients with AVB during UTT require a pacemaker implant.

Implante de cardiodesfibrilador automatico transvenoso en paciente con vena cava superior izquierda persistente / Implantation of a transvenous desfibrilation system in a patient with persistent left superior vena cava

La persistencia de la vena cava superior izquierda se observa en el 0.5por cento de la población. Describimos la técnica para el implante transvenoso del electrodo para DAI en VD, utilizando electrodos mas largos que los habituales y de fijación activa dada la rigidez de los mismos. La mayor experiencia de los equipos implantadores, asi como la mejor tecnología de los electrodos, permite el implante de sistemas endocavitarios, aun en pacientes con ausencia de vena cava superior derecha

El traumatizado grave: definición, aspectos pronósticos y evolutivos / The severe trauma patient: definition, prognosis and evolutive aspects

El traumatizado, y particularmente el traumatizado grave, continúa siendo un desafio diagnóstico, terapéutico y pronóstico. En el análisis de 37 traumatizados que ingresaron en una unidad de cuidados intensivos se realizó: a) la comparación de la capacidad predictiva de mortalidad intrahospitalaria de los índices de cuantificación anatómica de la injuria (ISS) y de los de alteración fisiologica secundaria al trauma (APACHE II) versus su combinación ("Doble Producto" = ISS X APACHE II al ingreso). Se confirmó que el "Doble Producto" mejora la especificidad de aquéllos por separado. b) la identificación de las complicaciones más destacables y la frecuencia de presentación de la Falla Orgánica Múltiple (FOM) y su vinculación con la mortalidad. Pasada la etapa de resucitación, la causa más frecuente de FOM fue la sepsis que, a su vez, fue la responsable final de la mayor parte de las muertes. La FOM se asoció significativamente con la mortalidad. Lo que antecede pretende mejorar la definición del traumatizado grave y basar los criterios pronósticos en datos objetivos y dinámicos