RESUMO
Objective To investigate the mechanism and prevention of syncope on patients with hypertrophic cardiomyopathy (HCM). Methods Seventy-six cases of HOCM (obstruction group) were successfully operated by PTSMA and oral ACEI/ARB. After six months , they were treated with β-receptor blocker. Another 29 patients (control group) with LVOTPG < 50 mmHg or < 70 mmHg after pharmacologic stress test (PST), have being treated with β-receptor blocker. The results was observed as follow: (1) the difference of between syncope incidence and positive incidence induced by PST in control group; (2) the difference of syncope incidence at half year, a year and admission in control group; (3) the difference of syncope incidence in obstruction group before and after operation; (4) the difference of syncope incidence after six months between two groups at same period; (5) the difference of syncope incidence one year between two groups. Results In control group, the syncope positive incidence induced PST was 55.5%. Treating with medications for half a year , syncope incidence significantly dropped than that on admission (P < 0.05); Obstruction group syncope incidence in the history obviously lower than the control group syncope positive induced PST (P < 0.05), and half a year after takingβ-receptor blocker syncope incidence was significantly dropped than before (P < 0.01). Conclusions The mechanism of syncope with HOCM is not only obstruction but also neuronal reflex. PST is an very useful inspection item for screening the ablation indication, analysis syncope mechanism, and guiding clinical medication.β-receptor blocker is an effective drug on treating and preventing syncope with HCM.
RESUMO
Pharmacologic stress testing for myocardial perfusion imaging is a widely used noninvasive method for the evaluation of known or suspected coronary artery disease. The use of exercise for cardiac stress has been practiced for over 60 years and clinicians are familiar with its using. However, there are inevitabe situations in which exercise stress is inappropriate. A large number of patients with cardiac problems are unable to exercise to their full potential due to comorbidity such as osteoarthritis, vascular disease and pulmonary disease and a standard exercise stress test for myocardial perfusion imaging is suboptimal means for assessment of coronary artery disease. This problem has led to the development of the pharmacologic stress test and to a great increase in its popularity. All of the currently used pharmacologic agents have well-documented diagnostic value. This review deals the physiological actions, clinical protocols, safety, nuclear imaging applications of currently available stress agents and future development of new vasodilating agents.