Fragmented QRS for Risk Stratification in Patients Undergoing First Diagnostic Coronary Angiography / QRS Fragmentado para Estratificação de Risco em Pacientes Submetidos à Primeira Angiografia Diagnóstica

Abstract Background: Only a small proportion of patients referred for coronary angiography with suspected coronary artery disease (CAD) have the diagnosis of obstructive CAD confirmed by the exam. For this reason, further strategies for risk stratification are necessary. Objective: To investigate the relationship of the presence of fragmented QRS (fQRS) on admission electrocardiogram with angiographically detected CAD and CAD severity in patients without known vascular diseases and myocardial fibrosis, undergoing first diagnostic coronary angiography. Methods: We enrolled 336 consecutive patients undergoing coronary angiography for suspected CAD. The patients were divided into two groups according to the presence or absence of fQRS on admission. We compared the groups regarding the presence and severity of CAD. Results: Seventy-nine (23.5%) patients had fQRS on admission. There was not a statistically significant difference between patients with fQRS (41.8%) and non-fQRS (30.4%), regarding the presence of CAD (p = 0.059). However, there was a statistically significant difference between patients with fQRS and non-fQRS regarding the presence of stenotic CAD (40.5% vs. 10.5%, p<0.001) and multi vessel disease (25,3% vs. 5.1%, p<0.001). The frequency of fQRS was significantly higher in patients with SYNTAX score >22 compared to patients with SYNTAX score ≤22. Conclusions: Our findings suggest that fQRS may be an indicator of early-stage myocardial damage preceding the appearance of fibrosis and scar, and may be used for risk stratification in patients undergoing first diagnostic coronary angiography

Resumo Fundamento: Somente uma pequena proporção dos pacientes com suspeita de doença arterial coronariana (DAC), encaminhados para realizarem angiografia coronária, tem o diagnóstico de DAC obstrutiva confirmado pelo exame. Por isso, outras estratégias de estratificação de risco são necessárias. Objetivo: Investigar a relação da presença de QRS fragmentado (QRSf) no eletrocardiograma na admissão com DAC detectada por angiografia e gravidade da DAC em pacientes sem diagnóstico de doenças vasculares, ou fibrose miocárdica, submetidos à primeira angiografia coronária de diagnóstico. Métodos: Recrutamos 336 pacientes consecutivos que se submeteram à angiografia coronária por suspeita de DAC. Os pacientes foram divididos em dois grupos de acordo com a presença ou ausência de QRSf na admissão. Nós comparamos os grupos quanto à presença e gravidade de DAC. Resultados: Setenta e nove (23,5%) pacientes apresentaram QRSf na admissão. Não houve diferença estatisticamente significativa entre pacientes com QRSf (41.8%) e sem QRSf (30,4%) (p = 0,059) quanto à presença de DAC. No entanto, houve uma diferença estatisticamente significativa entre pacientes com e sem QRSf quanto à presença de DAC (40.5% vs. 10.5%, p < 0,001) e de doença de múltiplos vasos (25,3% vs. 5,1%, p < 0,001). A frequência de QRSf foi significativamente maior em pacientes com escore SYNTAX > 22 em comparação a pacientes com escore SYNTAX ≤ 22. Conclusões: Nossos achados sugerem que o QRSf pode ser um indicador de danos iniciais no miocárdio antecedendo o aparecimento de fibrose e cicatrização, e pode ser usado para estratificação de risco em pacientes submetidos à primeira angiografia coronária de diagnóstico.

An overlooked cause of resistant hypertension: upper airway resistance syndrome - preliminary results

OBJECTIVE: Upper airway resistance syndrome is a sleep-disordered breathing syndrome that is characterized by repetitive arousals resulting in sympathetic overactivity. We aimed to determine whether upper airway resistance syndrome was associated with poorly controlled hypertension. METHODS: A total of 40 patients with resistant hypertension were enrolled in the study. All of the patients underwent polysomnographic examinations and 24-hour ambulatory blood pressure monitoring to exclude white coat syndrome and to monitor treatment efficiency. Among 14 upper airway resistance syndrome patients, 2 patients had surgically correctable upper airway pathologies, while 12 patients were given positive airway pressure therapy. RESULTS: All patients underwent polysomnographic examinations; 22 patients (55%) were diagnosed with obstructive sleep apnea and 14 patients (35%) were diagnosed with upper airway resistance syndrome, according to American Sleep Disorders Association criteria. The patients with upper airway resistance syndrome were younger and had a lower body mass index compared with other patients, while there were no difference between the blood pressure levels and the number of antihypertensive drugs. The arousal index was positively correlated with systolic blood pressure level (p = 0.034; rs = 0.746), while the Epworth score and AHI were independent of disease severity (p = 0.435, rs = 0.323 and p = 0.819, rs = -0.097, respectively). Eight patients were treated with positive airway pressure treatment and blood pressure control was achieved in all of them, whereas no pressure reduction was observed in four untreated patients. CONCLUSIONS: We conclude that upper airway resistance syndrome is a possible secondary cause of resistant hypertension and that its proper treatment could result in dramatic blood pressure control. .

Evaluation of the mean platelet volume in patients with cardiac syndrome X

OBJECTIVE: Cardiac syndrome X is characterized by angina-lke chest pain, a positive stress test, and normal coronary arteries. A patient's mean platelet volume, which potentially reflects platelet function and activity, is associated with coronary atherosclerosis and endothelial dysfunction. The aim of the present study was to evaluate the mean platelet volumes of patients with cardiac syndrome X, those with coronary artery disease and normal subjects. METHODS: Two hundred thirty-six subjects (76 patients with cardiac syndrome X, 78 patients with coronary artery disease, and 82 controls) were enrolled in the study. All of the subjects were evaluated with a detailed medical history, physical examination, and biochemical analyses. The mean platelet volumes were compared between the three groups. RESULTS: The mean platelet volumes in the patients with cardiac syndrome X and with coronary artery disease were significantly higher than those that were observed in the control group. There were no significant differences in the mean platelet volumes between the cardiac syndrome X and the coronary artery disease groups. CONCLUSION: We have established that patients with cardiac syndrome X and coronary artery disease exhibit higher mean platelet volumes compared to controls. Patients with cardiac syndrome X exhibited higher mean platelet volumes compared to the controls, reflecting the presence of subclinical atherosclerosis. These findings suggest that, in addition to endothelial dysfunction, the presence of atherosclerosis may also contribute to the etiopathogenesis of cardiac syndrome X.