A myriad of EKG changes have described as associated with heat stroke [25] and [26] including sinus tachycardia, ST elevations, T wave inversions and QT prolongation. However, these changes are non-specific, seen with a number of other conditions and have been often attributed to accompanying electrolyte abnormalities. A prospective study of Hajj pilgrims [27] experiencing heat stroke noted QTc prolongation in 64% patients, followed by ST changes/depression, in 21% patients. However, many patients had underlying risk factors for coronary artery disease but further testing was not able to be pursued due to this being a highly mobile population [27]. ST segment changes (elevation and depression) compatible with myocardial ischemia have also been described in other case series of hyperthermia [21] and [28]. In another retrospective study of patients suffering from heat stroke, the incidence of ischemic ST changes (defined as ST depression of ≥ 2 mm) was 17.6% accompanied by segmental wall motion abnormalities observed on echocardiography in most of these patients [29]. Transient, acute heart failure and increased pulmonary vascular resistance, along with dilatation of the right ventricle and left ventricular sub-endocardial hemorrhage (in a clinic-pathological study) have been described in the literature [30] and [31]. These findings suggest that aggressive volume repletion in heat stroke patients must be done with caution especially in patients who manifest evidence of acute myocardial dysfunction. In our patient, her absence of risk factors for coronary artery disease and her status as a conditioned athlete made the diagnosis of EKG changes related to heat stroke likely; however despite this, she had evidence for transient myocardial necrosis with elevated CK-MB. These enzyme rises have been shown to be present, however, following vigorous exercise in the absence of heat stroke [32] and [33]. In unconditioned patients with risk factors for pre-existing coronary disease, these ECG changes may be more difficult to interpret and may portend a poorer prognosis.
A myriad of EKG changes have described as associated with heat stroke [25] and [26] including sinus tachycardia, ST elevations, T wave inversions and QT prolongation. However, these changes are non-specific, seen with a number of other conditions and have been often attributed to accompanying electrolyte abnormalities. A prospective study of Hajj pilgrims [27] experiencing heat stroke noted QTc prolongation in 64% patients, followed by ST changes/depression, in 21% patients. However, many patients had underlying risk factors for coronary artery disease but further testing was not able to be pursued due to this being a highly mobile population [27]. ST segment changes (elevation and depression) compatible with myocardial ischemia have also been described in other case series of hyperthermia [21] and [28]. In another retrospective study of patients suffering from heat stroke, the incidence of ischemic ST changes (defined as ST depression of ≥ 2 mm) was 17.6% accompanied by segmental wall motion abnormalities observed on echocardiography in most of these patients [29]. Transient, acute heart failure and increased pulmonary vascular resistance, along with dilatation of the right ventricle and left ventricular sub-endocardial hemorrhage (in a clinic-pathological study) have been described in the literature [30] and [31]. These findings suggest that aggressive volume repletion in heat stroke patients must be done with caution especially in patients who manifest evidence of acute myocardial dysfunction. In our patient, her absence of risk factors for coronary artery disease and her status as a conditioned athlete made the diagnosis of EKG changes related to heat stroke likely; however despite this, she had evidence for transient myocardial necrosis with elevated CK-MB. These enzyme rises have been shown to be present, however, following vigorous exercise in the absence of heat stroke [32] and [33]. In unconditioned patients with risk factors for pre-existing coronary disease, these ECG changes may be more difficult to interpret and may portend a poorer prognosis.
การแปล กรุณารอสักครู่..
