RESUMO
BACKGROUND: We will focus our attention in this article in the ECG changes of classical Prinzmetal angina that occur during occlusive proximal coronary spasm usually in patients with normal or noncritical coronary stenosis. RESULTS: The most important ECG change during a focal proximal coronary spasm is in around 50% of cases the appearance of peaked and symmetrical T wave that is followed, if the spasm persist, by progressive ST-segment elevation that last for a few minutes, and later progressively resolve. The most frequent ECG changes associated with ST-segment elevation are: (a) increased height of the R wave, (b) coincident S-wave diminution, (c) upsloping TQ in many cases, and (d) alternans of the elevated ST-segment and negative T wave deepness in 20% of cases. The presence of arrhythmias is very frequent during Prinzmetal angina crises, especially ventricular arrhythmias. The prevalence and importance of ventricular arrhythmias were related to: (a) duration of episodes, (b) degree of ST-segment elevation, (c) presence of ST-T wave alternans, and (d) the presence of >25% increase of the R wave. CONCLUSIONS: The incidence of Prinzmetal angina is much lower then 50 years ago for many reasons including treatment with calcium channel blocks to treat hypertension and ischemia heart disease and the decrease of smoking habits.
Assuntos
Angina Pectoris Variante/fisiopatologia , Estenose Coronária/fisiopatologia , Vasoespasmo Coronário/fisiopatologia , Eletrocardiografia , Taquicardia Ventricular/fisiopatologia , Consenso , HumanosRESUMO
Brugada syndrome is an inherited heart disease without structural abnormalities that is thought to arise as a result of accelerated inactivation of Na channels and predominance of transient outward K current (I(to)) to generate a voltage gradient in the right ventricular layers. This gradient triggers ventricular tachycardia/ventricular fibrillation possibly through a phase 2 reentrant mechanism. The Brugada electrocardiographic (ECG) pattern, which can be dynamic and is sometimes concealed, being only recorded in upper precordial leads, is the hallmark of Brugada syndrome. Because of limitations of previous consensus documents describing the Brugada ECG pattern, especially in relation to the differences between types 2 and 3, a new consensus report to establish a set of new ECG criteria with higher accuracy has been considered necessary. In the new ECG criteria, only 2 ECG patterns are considered: pattern 1 identical to classic type 1 of other consensus (coved pattern) and pattern 2 that joins patterns 2 and 3 of previous consensus (saddle-back pattern). This consensus document describes the most important characteristics of 2 patterns and also the key points of differential diagnosis with different conditions that lead to Brugada-like pattern in the right precordial leads, especially right bundle-branch block, athletes, pectus excavatum, and arrhythmogenic right ventricular dysplasia/cardiomyopathy. Also discussed is the concept of Brugada phenocopies that are ECG patterns characteristic of Brugada pattern that may appear and disappear in relation with multiple causes but are not related with Brugada syndrome.
Assuntos
Síndrome de Brugada/diagnóstico , Síndrome de Brugada/fisiopatologia , Eletrocardiografia/métodos , Consenso , Diagnóstico Diferencial , HumanosRESUMO
Sudden death (SD) is of cardiac origin in approximately 80-90% of the cases and represents one of the most important challenges of the modern cardiology. Evaluation and understanding of its epidemiological, clinical and histopathological characteristics can lead to better results in its management. In Spain was carried a multicenter study MUSA with two arms: 1/ EULALIA: histopathological aspects of SD and 2/ MUSIC: SD in heart failure with focus on identification of population groups at risk, pathophysiological mechanisms of development and clinical prognostic markers. The preliminary conclusions of both studies are the following: 1/ EULALIA trial: From the total 121 sudden deaths, 109 (90%) were of cardiac origin and of these 45% presented characteristics of myocardial hypertrophy. The histopathological findings reveled that in only 48% of cases acute ischemic heart disease was present. In the other cases of ischemic heart disease the sudden death was probably by arrhythmic origin related with the presence of old myocardial infarction. This is the most striking difference compared with Anglo-Saxon studies. In the 29 cases of ACS, 18 had eroded and combination of eroded and ruptured plaques. In the cases of non-ACS plaques were stable in 20, and combination of stable and vulnerable plaques in 7 cases. Statistically significant results as independent predictors of sudden death gave the following markers: history of MI, cephalization of vessels in thorax X-ray, left atrium size > 45 mm, high levels of NT-proBNP and PIP, LBBB on ECG recording and body mass index.