[Current concepts on sudden death]. / Conceptos actuales sobre la muerte súbita.

Sudden death is defined as the death occurring less than one hour before the onset of the patient's symptoms. It is a severe condition considered a public health issue in several countries and in ours, it accounts for 33 000 to 53 000 annual deaths mainly related to ischemic heart disease. The main cause of sudden death are severe ventricular arrhythmias, but determining what patients are at risk for such an episode is complex, that is why risk stratification is usually a low cost-effective intervention. In the present study, we describe different sudden death risk-stratification strategies. Different sudden death treatment strategies regarding general population have different success rates in different countries, nevertheless, among select high risk populations; the best therapy currently available is the automatic implantable cardioverter-defibrillator. We also discuss other treatment options. In Mexico it is deemed necessary to do an important effort for the early detection, prevention and treatment of sudden death in order to limit the consequences of this problem.

Clinical findings as predictors of positivity of head-up tilt table test in neurocardiogenic syncope.

BACKGROUND: Neurocardiogenic (vasovagal) syncope occurs frequently and can be diagnosed with the head-up tilt table (HUTT) test. Our objective in this study was to identify clinical predictors of the positivity of HUTT test in neurocardiogenic syncope. METHODS: We conducted a prospective study of 117 cases (81 women and 36 men, 13-85 years of age) referred to our Institution for HUTT testing. The ability of 10 symptoms and signs of clinical history to predict HUTT positivity were evaluated using logistic regression analysis. RESULTS: We observed a low rate of test-negative cases (24%) and 89 positives. Nearly all positives (87/89) were neurocardiogenic, principally of vasodepressor and mixed types (43 and 34 cases, respectively) and a few were cardioinhibitory (10, mostly young males). Regression analysis established that dizziness, nausea, and diaphoresis in past history were associated with HUTT positivity nearly 25 times more frequently than when absent. CONCLUSIONS: Our three conclusions are that syncope in absence of heart disease accompanied by dizziness, nausea, and diaphoresis may be treated as neurocardiogenic in settings where no HUTT is available. In addition, our low rate of negative tests may have been the result of our reexamining referrals prior to deciding test performance, and high frequency of young males in cardioinhibitory syncope needs further research.

[Description of the resting electrocardiogram in a series of patients with myasthenia gravis]. / Descripción del electrocardiograma en reposo de una serie de pacientes con miastenia gravis.

UNLABELLED: Myasthenia gravis (MG) is a disease characterized by the presence of acetylcholine receptor-directed autoantibodies. Functional cardiac disorders are the most common since there is no neuro-muscular plate in the heart. Autonomic nervous system is involved in MG, but the cardiac manifestations of such an involvement remain unclear. Previous EKG studies in patients with MG show heterogeneous results. MATERIAL AND METHODS: A retrospective, descriptive and observational study was performed to know the main electrocardiographic characteristics and some autonomic nervous function in a series of patients with MG. RESULTS: One-hundred seventeen patients with EKG were analyzed. Twenty-eight were 47.9 +/- 20 years-old males, and 89 were women of 35.2 +/- 7.7 years (p = 0.001). 49 (41.9%) EKG had no changes, while 68 (58.1%) did. The main QT dispersion was 35.5 +/- 18.4 ms among those with some anomaly (p = 0.27). In 54 (78.3%) patients with an abnormal EKG there was T wave alternans, which was also present in 35 (71.4%) (p = 0.32) patients with normal EKG. CONCLUSIONS: MG is frequently associated to unspecific EKG changes. Dynamic electrocardiography allows a precise evaluation of the kind of cardiac involvement derived from MG, specifically the one related to the autonomic function, that is apparently affected in both the sympathetic and parasympathetic arms.

[Renal artery stenosis after transplantation: treatment using percutaneous transluminal angioplasty and placement of an expandable metal luminal prosthesis]. / Estenosis arterial renal posterior a trasplante: tratamiento con angioplastia transluminal percutánea y colocación de endoprótesis luminal metálica expandible.

UNLABELLED: Transplant renal artery stenosis (TRAS) is a cause of severe post transplant hypertension with a widely variable reported incidence from 1 to 25%. We herein report 3 cases of endoluminal stent placement after percutaneous transluminal angioplasty for treatment of TRAS. Clinical and laboratory findings during their follow-up, suggestive of TRAS included: elevated mean blood pressure, bruit over the graft area(2/3), and increase in serum creatinine (2/3). Doppler sonography, radioisotope renography and arteriography were performed to confirm TRAS diagnosis. The series includes 2 female and 1 male patients; the time elapsed between transplantation and TRAS diagnosis was 25 d, 12 and 65 months, respectively. All grafts were from living related donors. Patients received at least 3 antihypertensive drugs without adequate blood pressure control. Vascular anastomosis was end to end from the renal to the hypogastric artery in two cases, and end to side to the external iliac artery in the other one. After the diagnosis of TRAS, percutaneous transluminal angioplasty with endoluminal metallic Palmaz stent placement was accomplished in the three cases. No complications occurred during or after the procedures. Beneficial clinical results were obtained in all cases documented by a decrease in both: serum creatinine, and mean blood pressure. Average follow-up after stent placement was 13, 19 and 36 months, respectively without evidence of stenosis recurrence CONCLUSIONS: Percutaneous transluminal angioplasty with stent placement is a safe and effective treatment for TRAS associated hypertension and renal dysfunction. Extended follow-up is necessary to evaluate long-term efficacy and safety of this procedure.

Detection of myocardial viability could be improved by rest GIK (glucose-insulin-potassium solution)-Tc 99m sestamibi compared with TL-201 reinjection, in post myocardial infarction patients.

UNLABELLED: GIK solutions improve detection of myocardium viability after acute infarction because they could change the metabolic conditions, improving myocardial perfusion defects. METHODS AND RESULTS: Seventy four patients (52 men, 22 women, mean age 53.3.08 +/- 12.14 years) with previous myocardial infarction (evolution time, 4.2 +/- 3.1 months) underwent pharmacological stress (dipyridamole), rest redistribution and reinjection Tl-201 image as well rest/stress Tc-99m Sestamibi, after the intravenous administration of GIK (200 g glucose +/- 30 UI regular insuline +/- 40 mEq potassiumchloride/500 mL in continuous infusion during 3 hours), Group A (N = 22) or oral administration of 70 g of glucose+/- 40 mEq of potassium chloride taking in advantage the endogenous insulin secretion, to non-diabetic patients (group B = GB, N = 26) and group C (GC, diabetic patients N = 26). All of the 74 patients received 10 mg of sublingual Isorbide previous to 25 mCi of Tc99m Sestamibi administration in a different 2 days protocol. A total of 1,480 myocardial segments were assessed and numbered, and the severity of perfusion defects in the segments involved, were compared between Thallium 201 rest reinjection and GIK-MIBI as the main objective of the study. Involved territories number: 4.02 +/- 2.50 vs. 6.88 +/- 2.12, p = 0.005 for AD; 5.2 +/- 1.44 vs. 6.35 +/- 1.11, p = 0.05 for RC and 1.58 +/- 1.01 vs. 2.05 +/- 1.05, p = 0.05 Cx. For GIK-MIBI vs. Tl-201 reinjection respectively, and defect severity: 8.2 +/- 6.04 vs. 13.22 +/- 5.38, p = 0.01 for LAD; 11.72 +/- 5.08 vs. 15.13 +/- 4.42, p = 0.005 for RC and 2.66 +/- 2.09 vs. 4.69 +/- 3.58, p = 0.003 Cx . For GIK-MIBI vs. Tl-201 reinjection respectively, were found. CONCLUSION: Our data suggest that GIK-MIBI protocol is a safe and easy procedure which improves the detection of perfusion reversible defects compared with Tl-201 reinjection, obtaining better information regarding myocardial viability, with lower acquisition time and less cost.

[Impact of optimal medical therapy on the arrhythmias and heart rate variability detected with 24 hour Holter in a series of patients from a heart failure clinic]. / Impacto de la terapia médica en las arritmias y variabilidad de la frecuencia cardiaca detectadas por Holter de 24 horas en una serie de pacientes de una clínica de insuficiencia cardiaca.

UNLABELLED: Pharmacological treatment of heart failure (HF) patients usually induces improvements in their functional class (FC). Heart rate variability and Holter-detected arrhythmias are sudden cardiac death predictors and should be evaluated in the presence of optimal medical treatment. METHODS: We conducted a prospective, observational and linear study to evaluate ventricular arrhythmia presence and heart rate variability through 24-hr Holter. A first recording was made upon admission to the HF clinic and the second was obtained when a stable FC was reached or optimal medication doses where attained. RESULTS: We have controls among 47 patients 11.6 +/- 8.1 months after the enrollment Holter. We have 26 (55.3%) men, with an average age of 60.2 +/- 13.9 years. The main ejection fraction (EF) went from 31.9 to 37.4% during follow-up (p = 0.01). At enrollment, 44.7% of our patients were in a FC I, 27.7% in FC II and 27.7% in FC III. At the end of follow-up, 67.4% were in FC I, 27.9% in FC II and 4.7% in FC III. Time-domain variability did not show significant changes and remained in normal average values. Premature atrial contractions diminished (324.1 +/- 811.1 vs. 316 +/- 809.2) but the ventricular ones went from 1,493.6 +/- 3,530.9 in 24 hours, to 1,582.4 +/- 4,394.5 (p = ns) during control, among those with an EF < 40% and SDNN < 100 ms, we found an increase from 7,026.6 +/- 12,168.8 to 9,336 +/- 16,137.8 PVC's in 24-hours (p = 0.008). CONCLUSION: Optimal medical therapy for heart failure can positively change certain aspects of these patients, but it does not improve the arrhythmic sudden death risk profile.

Conceptos actuales sobre la muerte súbita / Current concepts on sudden death

La muerte súbita se define como aquella que ocurre antes de una hora de la aparición de los síntomas. Es una condición grave que en diversos países supone un problema de salud pública y que en México implica entre 33 y 53 mil muertes anuales, en su mayoría ligadas a enfermedad isquémica del corazón. La causa primordial de la muerte súbita son las arritmias ventriculares graves, sin embargo determinar qué sujetos son susceptibles de tener un episodio arrítmico es complejo y por ello la relación costo efectividad de las medidas de estratificación de riesgo suele ser mala. En el presente trabajo se revisan las diferentes estrategias para determinar el riesgo de muerte súbita. Las estrategias para el tratamiento oportuno de la muerte súbita relativas a la población general utilizadas en diversos países tienen impactos variables en la supervivencia, sin embargo, en las poblaciones seleccionadas con alto riesgo de padecer un evento arrítmico ventricular, la mejor terapia disponible actualmente es el desfibrilador automático implantable, aunque en el trabajo se discuten otras opciones de tratamiento. En nuestro país es necesario hacer un importante esfuerzo de detección prevención y tratamiento oportuno para limitar las consecuencia de este problema.

Sudden death is defined as the death occurring less than one hour before the onset of the patient's symptoms. It is a severe condition considered a public health issue in several countries and in ours, it accounts for 33 000 to 53 000 annual deaths mainly related to ischemic heart disease. The main cause of sudden death are severe ventricular arrhythmias, but determining what patients are at risk for such an episode is complex, that is why risk stratification is usually a low cost-effective intervention. In the present study, we describe different sudden death risk stratification strategies. Different sudden death treatment strategies regarding general population have different success rates in different countries, nevertheless, among select high risk populations; the best therapy currently available is the automatic implantable cardioverter defibrillator. We also discuss other treatment options. In Mexico it is deemed necessary to do an important effort for the early detection, prevention and treatment of sudden death in order to limit the consequences of this problem.

Síndrome carcinoide: reporte de un caso con afección cardiaco y tumor primario de ovario / Carcinoid syndrome: report of a case with cardiac involvement and primary tumor of the ovary

Se presenta el caso de una paciente con tumor carcinoide primario de ovario que desarrolló enfermedad cardiaca carcinoide grave sin metástasis hepáticas. Se hace una revisión de la literatura, enfatizando el hecho de que la enfermedad cardiaca carcinoide secundaria a tumor ovárico primario es muy rara. Se discuten las indicaciones quirúrgicas relativas a este caso.

Kearns-Sayre syndromes and absolute indication for prophylactic implantation of definitive pacemaker?

El síndrome de Kearns-Sayre es una citopatía mitocondrial caracterizada por oftalmoplejia externa crónica progresiva, retinopatía pigmentaria y bloqueo auriculoventricular, siendo este último el determinante de la supervivencia de estos enfermos. Presentamos el caso de un hombre de 23 años con síndrome de Kearns-Sayre con trastornos de la conducción y prolapso de la válvula mitral. Se describen las características de este síndrome, así como los criterios para la implantación profiláctica de marcapaso definitivo

Multiple recurring paragangliomas: A problem of diagnosis and location. Case report and review of the literature

Exposición. El diagnóstico de paragangliomas múltiples constituye un reto clínico por la dificultad de identificar la presencia y localización de las lesiones. Reporte del caso. Se presentan los hallazgos clínicos y paraclínicos del caso de una mujer joven con paragangliomas múltiples que recidivan once años después del tratmaiento quirúrgico exitoso. Discusión. El caso ilustra las dificultades diagnósticas de esta entidad y la ausencia de procedimientos suficientemente sensibles para detectar la presencia de uno o más tumores con o sin producción hormonal, su localización, características de crecimiento y el número de éstos, para evitar, como ha ocurrido, múltiples intervenciones quirúrgicas. En ausencia de una técnica ideal para el diagnóstico y localización de este tipo de tumor, los métodos no invasivos, particularmente la gammagrafía con 131I MIBG, juega un papel muy significativo en esta evaluación, por su alta sensibilidad para detectar la presencia de tejido cromafín, especialmente en localizaciones extraadrenales. Conclusión. El rastreo periódico a largo plazo con 131I MIBG para todos los pacientes asintomáticos con riesgo de tejido tumoral residual o recidivante, benigno o metastásico, debiera ser una rutina recomendable