Adverse Effects Associated With the Use of Antimalarials During The COVID-19 Pandemic in a Tertiary Care Center in Mexico City.

Background: Antimalarial drugs were widely used as experimental therapies against COVID-19 in the initial stages of the pandemic. Despite multiple randomized controlled trials demonstrating unfavorable outcomes in both efficacy and adverse effects, antimalarial drugs are still prescribed in developing countries, especially in those experiencing recurrent COVID-19 crises (India and Brazil). Therefore, real-life experience and pharmacovigilance studies describing the use and side effects of antimalarials for COVID-19 in developing countries are still relevant. Objective: To describe the adverse effects associated with the use of antimalarial drugs in hospitalized patients with COVID-19 pneumonia at a reference center in Mexico City. Methods: We integrated a retrospective cohort with all adult patients hospitalized for COVID-19 pneumonia from March 13th, 2020, to May 17th, 2020. We compared the baseline characteristics (demographic and clinical) and the adverse effects between the groups of patients treated with and without antimalarial drugs. The mortality analysis was performed in 491 patients who received optimal care and were not transferred to other institutions (210 from the antimalarial group and 281 from the other group). Results: We included 626 patients from whom 38% (n = 235) received an antimalarial drug. The mean age was 51.2 ± 13.6 years, and 64% were males. At baseline, compared with the group treated with antimalarials, the group that did not receive antimalarials had more dyspnea (82 vs. 73%, p = 0.017) and cyanosis (5.3 vs. 0.9%, p = 0.009), higher respiratory rate (median of 28 vs. 24 bpm, p < 0.001), and lower oxygen saturation (median of 83 vs. 87%, p < 0.001). In the group treated with antimalarials, 120 patients had two EKG evaluations, from whom 12% (n = 16) prolonged their QTc from baseline in more than 50 ms, and six developed a ventricular arrhythmia. Regarding the trajectories of the liver function tests over time, no significant differences were found for the change in the mean value per day between the two groups. Among patients who received optimal care, the mortality was 16% (33/210) in those treated with antimalarials and 15% (41/281) in those not receiving antimalarials (RR 1.08, 95% 0.75-1.64, and adjusted RR 1.12, 95% CI 0.69-1.82). Conclusion: The adverse events in patients with COVID-19 treated with antimalarials were similar to those who did not receive antimalarials at institutions with rigorous pharmacological surveillance. However, they do not improve survival in patients who receive optimal medical care.

Bilateral Proximal Forearm Transplantation: Case Report at 7 Years.

BACKGROUND: Although return of function has been reported in patients undergoing proximal forearm transplantations (PFTs), reports of long-term function are limited. In this study, we evaluated the clinical progress and function 7 years postoperatively in a patient who underwent bilateral PFT. CASE PRESENTATION: A 58-year-old man underwent bilateral PFT in May 2012. Transplantation involved all of the flexor and extensor muscles of the forearm. Neurorrhaphies of the median, ulnar, and radial nerves were epineural and 7 cm proximal to the elbow. Immunosuppressive maintenance medications during the first 3 years postoperatively were tacrolimus, mycophenolate, and steroids, and later, tacrolimus, sirolimus, and steroids. Forearm function was evaluated annually using the Disabilities of the Arm, Shoulder, and Hand; Carroll; Hand Transplantation Score System; Short Form-36; and Kapandji scales. We also evaluated his grip and pinch force. RESULTS: Postoperatively, the patient developed hypertriglyceridemia and systemic hypertension. He experienced 6 acute rejections, and none were resistant to steroids. Motor function findings in his right/left hand were: grip strength: 10/13 kg; key pinch: 3/3 kg; Kapandji score: 6/9 of 10; Carroll score: 66/80; Hand Transplantation Score System score: 90/94. His preoperative Disabilities of the Arm, Shoulder, and Hand score was 50 versus 18, postoperatively; his Short Form-36 score was 90. This function improved in relation with the function reported in the second year. CONCLUSIONS: Seven years following PFT, the patient gained limb strength with a functional elbow and wrist, although with diminished digital dexterity and sensation. Based on data presented by other programs and our own experience, PFT is indicated for select patients.

Effects of thalidomide treatment in heart failure patients.

BACKGROUND: Several studies have reported a direct association between elevated plasma levels of inflammatory cytokines and worse functional class (New York Heart Association [NYHA]) and cardiac function, measured as left ventricular ejection fraction (LVEF). Thalidomide has recently shown to improve LVEF in chronic heart failure patients, accompanied by a marked decrease in plasma levels of tumor necrosis factor alpha (TNF-alpha). METHODS: In a randomized prospective open label study of men and women with heart failure (HF) due to ischemic and non-ischemic cardiomyopathy who had systolic dysfunction (LVEF <40%) and NHYA classification, functional classes II and III were assigned to control (without thalidomide, 60 patients) or thalidomide group (20 patients). The initial dose of thalidomide was 100 mg once a day, and it was increased to 100 mg twice a day after a period of 10 days, if the prior dosage was well-tolerated. Demographic characteristics, etiology of HF, prior myocardial infarction, co-morbidities associated were registered and laboratory routine test, TNF-alpha serum levels, and echocardiogram were obtained at the beginning and after 6 months of follow-up. RESULTS: Clinical status (NYHA) at the end of the follow-up period, improved moderately in both groups. TNF-alpha levels were initially of 5.88 +/- 0.9 and 6.49 +/- 1.82 vs. 6.32 +/- 1.6 and 7.94 +/- 3.8 pg/ml during follow-up, for thalidomide and control groups, respectively. There were non-significant differences in echocardiography variables. CONCLUSION: In conclusion, although there is a large amount of information supporting a direct relationship between TNF-alpha and worsening of symptoms and prognosis in patients with HF and recently, the beneficial effect on thalidomide treatment has been suggested, these preliminary observations should be confirmed in a larger prospective study, specially trying to clarify the action mechanisms.

Bioelectrical impedance and strength measurements in patients with heart failure: comparison with functional class.

OBJECTIVE: Patients with chronic heart failure (HF) develop important changes in body composition. Nevertheless, the usual methods of body composition assessment can be misleading in patients with HF because tissue hydration is altered. Bioelectrical impedance vector analysis (BIVA) works without making any assumption about constant soft tissue hydration. In this study, patients with HF and systolic dysfunction (HFS) and preserved systolic function (HFPSF) underwent a body composition evaluation by the BIVA method; the comparison was done between New York Heart Association (NYHA) functional classes I-II and III-IV. METHODS: We studied 243 patients with HF, 140 (101 in NYHA I-II and 39 in III-IV) with HFS and 103 (67 in NYHA I-II and 36 in II-IV) with HFPSF. Whole-body bioelectrical impedance was measured using BodyStat QuadScan 4000, which is tetrapolar and multiple-frequency equipment. RESULTS: In both HF categories, reactance and phase angle were significantly lower, the impedance ratio of 200 kHz to that at 5 kHz was higher, and had significantly shorter and downsloping impedance vector in the NYHA III-IV group compared with the NYHA I-II group by gender. CONCLUSION: Bioelectrical impedance analysis allows an easier evaluation of body composition and this might be particularly useful to stratify the severity of HF.

Aldosterone receptor antagonists induce favorable cardiac remodeling in diastolic heart failure patients.

BACKGROUND: Serum levels of aldosterone in heart failure are increased up to 20 times compared to normal subjects. After an acute myocardial infarction, aldosterone increases progressively as well as interstitial fibrosis and collagen synthesis from cardiac fibroblasts, forming a patchy heterogeneous interstitial collagen matrix that affects ventricular function. Even if angiotensin converting enzyme inhibitors (ACEI) or angiotensin II receptor antagonists (ARA) can reduce aldosterone levels early during treatment, they increase again after a 12 week treatment. The aim of this study was to evaluate the changes in structure and function of the left ventricle in symptomatic (NYHA I-III) diastolic heart failure patients receiving an aldosterone receptor antagonist. METHODS: Twenty-eight subjects with diastolic heart failure, on BB, ACEI and/ or ARA were randomized to receive spironolactone (group A) on a mean dose of 37.5 mg once a day (n = 14, age 63.7 +/- 21.6 years and body mass index, BMI 27.5 +/- 9.4), or not (group B, n = 14, Age 64.8 +/- 11.9, BMI 26.9 +/- 4.7). All patients were followed-up for a mean of 13.79 +/- 0.99 months. RESULTS: Group A showed a 42.8% ischemic origin of heart failure, while in group B was 55% (p = 0.2). No other co-morbidities were significativelly different among both groups. Mean percentage of changes by echocardiogram was as follows: Interventricular septum (IVS) -12.2 +/- 11% vs. 1.3 +/- 15.2 (p = 0.03), pulmonary systolic artery pressure (PSAP was 0.99 +/- 3.8% vs. 10.5 +/- 9.1, p = 0.05). Other parameters did not show statistically significant differences. CONCLUSION: Aldosterone receptor antagonists reduce or avoid increasing of PSAP and inducing a favorable remodeling of the left ventricle, especially in the IVS in diastolic heart failure patients.

Body composition and echocardiographic abnormalities associated to anemia and volume overload in heart failure patients.

BACKGROUND: Heart failure (HF) patients with hemodilutional anemia had a worse prognosis than those with true anemia. Volume overload (VO) in anemic patients must be identified in order to select the best treatment. METHOD: We assessed the prevalence of anemia and VO in systolic and diastolic HF patients, and its effects on clinical status, body composition, and quality of life (QOL). Anemia was defined according to the OMS criteria and VO was assessed by bioelectrical impedance analysis (BIA). Echocardiography variables were also obtained. RESULTS: We studied 132 HF patients, 59.1% with systolic and 40.9% with diastolic HF. Anemia was present in 29.5% patients with systolic and 24.1% with diastolic HF (P=0.7). Anemic patients in the systolic HF group tend to be worse functional class than the non-anemic subjects; moreover, in both groups of cardiac dysfunction, the anemic patients had less grip strength, lower body mass index (BMI) and waist and hip circumferences, and a higher percentage of extracellular water (ECW), a higher proportion of patients with total serum cholesterol concentration below the 25th percentile, and a lower serum albumin. When patients were divided in 4 subgroups according to the presence of anemia and/or VO, we observed that VO affected the body composition not only through lower BMI, and waist and hip circumferences but also through a lower phase angle. Systolic HF patients with anemia and VO had the highest dimension of left atrium and pulmonary artery pressure (PAP) levels. CONCLUSION: Anemia is common in HF and its prevalence is similar in systolic and diastolic HF patients. Anemia was associated to VO, less grip strength and body composition abnormalities; however, VO was related to more severe body composition and echocardiographic abnormalities, as well as to an impairment of QOL. So that, it is important to differentiate between those who have anemia associated to VO and those who have true anemia.

[Differential behaviour of blood pressure in patients with neurocardiogenic syncope during the initial stage of the tilt table test]. / Comportamiento diferencial de la tensión arterial de pacientes con síncope neuro-cardiogénico en la fase inicial de la prueba de inclinación.

UNLABELLED: Neurocardiogenic syncope (NCS) is diagnosed by means of a head-up tilt table tests (HUTT). This is a prolonged test although early outcome predictors are known. METHODS: We conducted a study among patients engaged in a syncope study protocol. We performed HUTT in all of them and compared the basal arterial pressure with the arterial pressure at the end of a the 70 degrees tilting. RESULTS: We performed 185 HUTT studies. Systolic blood pressure (BP) raised 0.9% among patients with a negative test, whereas patients with a positive HUTT showed a 2.3% decrease (p = 0.2) in the same measurement. Diastolic BP increased 34% among negative HUTT patients and 14.9% among patients with positive test (p = 0.02). We calculated a relative risk of 1.45 for positive test when the combination of systolic BD decrease and dyastolic increase was present, according to the percentage of change (IC95%: 1.1 to 7.8). CONCLUSIONS: The combination of systolic BP reduction and diastolic BP elevation at the end of the 70 degrees tilting is associated with an increased risk of having a positive HUTT. These changes might be related to differential sympathetic stimulation.

Abnormal SPECT myocardial perfusion imaging during periods of obstructive sleep apnea in morbid obese patients without known heart disease.

OBJECTIVE: Determine the myocardial perfusion characteristics in obstructive sleep apnea and its possible role in cardiovascular damage. METHODS AND PROCEDURES: Fourteen patients from the Obesity Clinic weighing less than 130 kg underwent myocardial perfusion studies using single photon emission computed tomography with technetium 99m-labeled sestamibi during nighttime polysomnographic recordings. Coronary angiograms were performed on patients with suspect of severe coronary obstruction according nighttime myocardial perfusion studies or pharmacological stress carried out during waking hours. RESULTS: All 14 patients manifested myocardial perfusion defects during sleep, affecting an average of 5.5 segments/patient, although only 8 presented ischemic ST segment changes and none demonstrated rhythm or conduction disturbances. Angiographic examination of the 10 patients with the most severe perfusion defects did not reveal significant coronary obstruction, and fewer perfusion defects were documented during daytime scintigraphy. DISCUSSION: In obese patients with obstructive sleep apnea, myocardial perfusion defects appear to occur with highest frequency and severity during nighttime sleep, justifying further investigation in a larger number of patients with obstructive sleep apnea and more significant obesity.

Effect of ivabradine on endothelial function in diastolic and right heart failure patients.

Background. Ivabradine is an If ion current inhibitor that has proved to reduce mortality in patients with systolic heart failure by slowing heart rate without decreasing myocardial contractility. Photoplethysmography is a simple, low-cost optical technique that can evaluate vascular function and detect changes in blood flow, pulse, and swelling of tissular microvascular space. Objective. To evaluate the effect of ivabradine on endothelial function by photoplethysmography in diastolic and right heart failure patients. Methodology. 15 patients were included (mean age of 78.1 ± 9.2 years) with optimally treated diastolic and right heart failure. They underwent photoplethysmography before and after induced ischemia to evaluate the wave blood flow on the finger, using the maximum amplitude time/total time (MAT/TT) index. Two measurements were made before and after oral Ivabradine (mean 12.5 mg a day during 6 months of followup). Results. In the study group, the MAT/TT index was 29.1 ± 2.2 versus 24.3 ± 3.2 (P = 0.05) in basal recording and 30.4 ± 2.1 versus 23.3 ± 2.9 (P = 0.002), before versus after ischemia and before versus after Ivabradine intervention, respectively. Conclusions. Ivabradine administration improves endothelial function (shear stress) in diastolic and right heart failure patients.

Prognostic value of cardiac troponin T elevation is independent of renal function and clinical findings in heart failure patients.

BACKGROUND: The aim of this study is to determine the prevalence and prognostic value of elevated cardiac troponin (cTnT) and its association with clinical characteristics according to renal function status in patients with stable heart failure. METHODS: In a prospective observational study, 152 consecutive patients from the Heart Failure Clinic of the INCMNSZ were followed for a period of 42 months. All underwent clinical evaluation, echocardiography, and determination of body composition by electric bioimpedance to identify hypervolemia. Concentrations of cTnT were quantified by immunoassay with electrochemoluminescence and > or = 0.02 ng/mL levels were considered elevated. Also glomerular filtration rate (eGFR) was estimated using the Cockcroft-Gault equation. RESULTS: Elevated cTnT was significantly associated with increased all-cause mortality in the observational period even after adjusting for eGFR < 60 mL/min/1.73 m2 and clinical findings such as hypertension, functional class, loop diuretics, angiotensin converting enzyme inhibitors, pulmonary pressure and hypervolemia in Cox regression analysis with a hazard ratio of 4.58 (95% confidence interval: 1.84-11.45). CONCLUSIONS: Heart failure patients with elevated cardiac-specific troponin T are at increased risk of death independently of the presence of chronic kidney disease.

Changes in the arrhythmic profile of patients treated for heart failure are associated with modifications in their myocardial perfusion conditions.

BACKGROUND: Heart failure (HF) patients can benefit from a proper RS. We had observed that they show an increase in the number of arrhythmias during the first year of pharmacological treatment. METHODS: We carried out a prospective observational study in which patients in an HF Clinic were included when they had follow-up Holter monitoring. Patients also had a baseline myocardial perfusion scan (Tc99 sestaMIBI/dypiridamole) and a control scan. RESULTS: We included 90 patients with follow-up Holter and 35 with scintigraphy, for analysis. Fifty-six (62.2%) were men and the average age was 60.8 +/- 14.6 years. Follow-up periods were divided by six-month intervals up to 18 months or more, an increase in premature ventricular contractions (PVCs) occurred in the six-month to one-year period (1915.4 +/- +/- 4686.9 vs. 2959 +/- 6248.1, p = 0.09). In the one-year to 18-month control, PVCs went from 781.6 +/- 1082.4 to 146.9 +/- 184.1, p = 0.05. The increase in PVCs correlated with a reduction in scintigraphy-detected ischemic territories, 5.64 +/- 5.9 vs. 3.18 +/- 3 (p = 0.1) and a gain in those showing a reverse redistribution pattern (0.18 +/- 0.6 vs. 2.09 +/- 4.01, p = 0.1). Necrotic territories and time domain heart rate variability did not show significant changes. CONCLUSIONS: PVCs increase during the first year of HF treatment, and then they tend to diminish and stabilize. These changes seem to correlate with changes in the perfusion state of the patient. While ischemic territories decrease, reverse redistribution increases, showing that endothelial dysfunction could have a relevant role in arrhythmia generation, possibly because of membrane instability of recovered hibernating myocardium.

Microalbuminuria in systolic and diastolic chronic heart failure patients.

BACKGROUND: Microalbuminuria is considered a major risk factor predisposing to cardiovascular morbidity and mortality. Microalbuminuria levels in patients with or without diabetes have been associated with a higher risk of chronic heart failure (HF). However, there are limited data regarding prevalence of microalbuminuria in chronic heart failure and its prognostic value. The aim of this study was to assess the occurrence of microalbuminuria in chronic heart failure patients as well as its association with clinical, echocardiographic, and body composition markers. METHODS: In a cross-sectional study, we included 72 chronic heart failure patients (NYHA I-III) on standard HF therapy. All patients had an echocardiogram and body composition by vector bioelectric impedance analysis (measured by Body Stat Quad Scan). RESULTS: The studied population consisted of 64% men at mean age of 62.6 +/- 15.1 years. Patients were divided into systolic and diastolic HF groups. Microalbuminuria was observed in 40% of diastolic and 24% systolic HF patients (p = 0.04). Microalbuminuria was present in more patients with volume overload (80 vs. 21.9%, p = 0.002), with a worse phase angle and lower serum albumin (4.7 vs. 5.9 degrees and 3.5 vs. 4.0 mg/dl, p = 0.02) and higher pulmonary arterial pressure compared with patients without microalbuminuria in systolic HF patients. There was no significant association between frequency of microalbuminuria and ejection fraction. In the diastolic HF group, the presence of microalbuminuria was not associated with any known risk factor. CONCLUSIONS: Microalbuminuria was more frequent in diastolic than systolic HF patients. In systolic HF patients microalbuminuria was associated with factors known to be markers of worse prognosis.

Aldosterone receptor antagonists induce favorable cardiac remodeling in diastolic heart failure patients / Antagonistas de receptores de aldosterona inducen remodelación cardiaca favorable en pacientes con insuficiencia cardiaca diastólica

Background. Serum levels of aldosterone in heart failure are increased up to 20 times compared to normal subjects. After an acute myocardial infarction, aldosterone increases progressively as well as interstitial fibrosis and collagen synthesis from cardiac fibroblasts, forming a patchy heterogeneous interstitial collagen matrix that affects ventricular function. Even if angiotensine converting enzyme inhibitors (ACEI) or angiotensin II receptor antagonists (ARA) can reduce aldosterone levels early during treatment, they increase again after a 12 week treatment. The aim of this study was to evaluate the changes in structure and function of the left ventricle in symptomatic (NYHA I-III) diastolic heart failure patients receiving an aldosterone receptor antagonist. Methods. Twenty-eight subjects with diastolic heart failure, on BB, ACEI and/or ARA were randomized to receive spironolactone (group A) on a mean dose of 37.5 mg once a day (n =14, age 63.7 ± 21.6 years and body mass index, BMI 27.5 ± 9.4), or not (group B, n = 14, Age 64.8 ± 11.9, BMI 26.9 ± 4.7). All patients were followed-up for a mean of 13.79 ± 0.99 months. Results. Group A showed a 42.8% ischemic origin of heart failure, while in group B was 55% (p = 0.2). No other co-morbidities were significativelly different among both groups. Mean percentage of changes by echocardiogram was as follows: Interventricular septum (IVS) -12.2 ± 11% vs. 1.3 ± 15.2 (p = 0.03), pulmonary systolic artery pressure (PSAP was 0.99 ± 3.8% vs. 10.5 ± 9.1, p = 0.05). Other parameters did not show statistically significant differences. Conclusion. Aldosterone receptor antagonists reduce or avoid increasing of PSAP and inducing a favorable remodeling of the left ventricle, especially in the IVS in diastolic heart failure patients.

Antecedentes. En pacientes con insuficiencia cardiaca existen aumentos de aldosterona hasta 20 veces mayores que en sujetos control. Después de un infarto miocárdico la aldosterona aumenta progresivamente, así como la fibrosis intersticial y la síntesis de colágena por fibroblastos cardiacos, provocando parches intersticiales heterogéneos en la matriz de colágena que afecta la función ventricular. El tratamiento inicial con inhibidores de enzima convertidora de angiotensina (IECA) y/o antagonistas de receptores de angiotensina II (ARA) puede reducir estos niveles; sin embargo, aumentan nuevamente después de 12 semanas de tratamiento. El propósito de este estudio fue evaluar los cambios estructurales y funcionales en el ventrículo izquierdo en pacientes con insuficiencia diastólica tratados con ARA angiotensina (NYHAI-III). Métodos. Veintiocho pacientes con insuficiencia cardiaca diastólica en tratamiento con BB, IECA y/o ARA se aleatorizaron a recibir una dosis media de 37.5 mg una vez al día de espironolactona (grupo A) (n - 14, edad 63.7 ± 0 21.6 años e índice masa corporal IMC 27.5 ± 9.4), o no (grupo B, n =14, edad 64.8 ± 11.9, IMC 26.9 ± 4.7). Todos los pacientes fueron seguidos por 13.79 ± 0.99 meses. Resultados. De los pacientes del grupo A, 42.8% y el 55 del grupo B (p = 0.2), tenían cardiopatía isquémica. No se encontraron diferencias significativas en otras comorbilidades. El porcentaje promedio de cambios en el ecocardiograma se observó en septum interventricular (SIV) -12.2 ± 11% vs. 1.3 ± 15.3% (p = 0.02), y la presión sistólica de la arteria pulmonar (PSAP, 0.99 ± 3.8% vs. 10.5 ± 9.1, p = 0.05, para los grupos A y B, respectivamente). Los otros parámetros no mostraron diferencias estadísticamente significativas. Conclusión. El tratamiento con antagonistas de receptores de aldosterona disminuye o limita aumentos de PSAP e inducen una remodelación favorable del ventrículo izquierdo, especialmente del SIV en pacientes con insuficiencia cardiaca diastólica.

Comportamiento diferencial de la tensión arterial de pacientes con síncope neuro-cardiogénico en la fase inicial de la prueba de inclinación / Differential behaviour of blood pressure in patients with neurocardiogenic syncope during the initial stage of the tilt table test

Neurocardiogenic syncope (NCS) is diagnosed by means of a head-up tilt table tests (HUTT). This is a prolonged test although early outcome predictors are known. METHODS: We conducted a study among patients engaged in a syncope study protocol. We performed HUTT in all of them and compared the basal arterial pressure with the arterial pressure at the end of a the 70 degrees tilting. RESULTS: We performed 185 HUTT studies. Systolic blood pressure (BP) raised 0.9% among patients with a negative test, whereas patients with a positive HUTT showed a 2.3% decrease (p = 0.2) in the same measurement. Diastolic BP increased 34% among negative HUTT patients and 14.9% among patients with positive test (p = 0.02). We calculated a relative risk of 1.45 for positive test when the combination of systolic BD decrease and dyastolic increase was present, according to the percentage of change (IC95%: 1.1 to 7.8). CONCLUSIONS: The combination of systolic BP reduction and diastolic BP elevation at the end of the 70 degrees tilting is associated with an increased risk of having a positive HUTT. These changes might be related to differential sympathetic stimulation.

Fibrilación auricular: nuevos aspectos sobre una vieja enfermedad / Atrial Fibrillation: new aspects of an old disease

La fibrilación auricular es la arritmia encontrada más frecuentemente en la clínica. Los principales problemas derivados de ella son los eventos trombóticos recurrentes y el deterioro de la clase funcional. La fibrilación auricular induce alteraciones de los canales iónicos, que la perpetoan. El tratamiento de la FA se encamina a corregir estas alteraciones y regresar al ritmo sinusal, al tiempo que se debe controlar la frecuencia cardiaca y prevenir eventos embólicos por medio de anticoagulación o tratamiento con antiagregantes plaquetarios. Actualmente existen recursos con antiarrítmicos de clase IC o clase III para intentar recuperar el ritmo sinusal. Las tasas de éxito son variables y las mejores se obtienen con flecainida o propafenona en los casos sin cardiopatía estructural y amiodarona cuando ésta existe. Las combinaciones de pacientes y fármacos son múltiples, cada caso debe ser individualizado. Los nuevos antiarrítmicos de clase III han mostrado eficacia pero con tasas relativamente altas de reacciones adversas como taquicardia helicoidal. La anticoagulación sería el tratamiento preferido para la mayoría de los enfermos, pero se debe ajustar en cada caso. Las terapias como la ablación con catéter focal o lineal, así como la estimulación auricular o biauricular y los desfibriladores implantables requieren de un seguimiento a mayor plazo y también necesitan de tratamiento antiarrítmico agregado. La cirugía tiene una morbi-mortalidad alta, por lo que el riesgo supera al beneficio.

Cardiac conduction distrurbances in mixed connective tissue disease

Objetivo: Determinar la prevalencia de trastornos de conducción cardiaca en pacientes con enfermedad mixta de tejido conectivo, atendidos en un instituto de la Ciudad de México y su relación con otras manifestaciones de la enfermedad. Método: Ciento trece pacientes admitidos en el Instituto con diagnóstico de enfermedad mixta de tejido conectivo fueron divididos en aquellos con alteraciones de conducción (n=23) y sin estos (n=90). Durante un período de seguimiento de 10.2 ñ 7.8 años, se examinaron, el curso clínico, duración de la enfermedad, tratamiento, tipos de trastornos de conducción y alteraciones sistémicas. Resultados: Observamos un marcado predominio de mujeres en ambos grupos. Las alteraciones de conducción ocurrieron en cerca de 20 por ciento de los pacientes con enfermedad mixta de tejido conectivo y no encontramos diferencias significativas entre los grupos durante el seguimiento. Como era de esperarse, una diferencia significativa entre ambos fue la desviación del aQRS, relacionado a la presencia del bloqueo de fascículo anterior de la rama izquierda del HH, la más frecuente de las alteraciones de conducción observadas. Durante el seguimiento un paciente del grupo A murió, pero ninguno en el grupo B. Conclusión: Las alteraciones de conducción estuvieron presentes en 20 por ciento, en concordancia con lo referido por otros autores en la literatura. Sin embargo, no participaron en la evolución de la enfermedad.