[Impact of blood pressure control on coronary flow reserve in hypertensive patients]

OBJECTIVE

To investigate the impacts of blood pressure control on coronary flow reserve (CFR) in hypertensive patients.

METHODS

A total of 236 patients without significant coronary stenosis (defined as <50% luminal narrowing which was confirmed by coronary angiography or coronary artery CT scan) between January 2011 to July 2015 were retrospectively enrolled in this study. CFR was measured in the left anterior descending coronary artery (LAD) during adenosine triphosphate-induced hyperemia by transthoracic Doppler echocardiography. Patients were divided into hypertension group (n=173) and non-hypertension group (n=63). The hypertension patients were further divided into ideally controlled (n=31, defined as SBP <120 mmHg (1 mmHg=0.133 kPa) and DBP <80 mmHg), controlled (n=82, defined as SBP 120 to 139 mmHg and DBP <90 mmHg) and uncontrolled groups (n=60, defined as SBP≥140 mmHg and/or diastolic DBP≥90 mmHg) based on their blood pressure after systematic antihypertensive therapy and CFR values were compared among the 4 groups. Multivariate regression analyses were performed to identify the independent determinants of CFR in patients with hypertension.

RESULTS

Compared with non-hypertension group, the CFR was significantly lower in controlled (3.27±0.71 vs. 2.87±0.56, P<0.001) and uncontrolled groups (3.27±0.71 vs. 2.61±0.71, P<0.001), but was similar in ideally controlled group (3.27±0.71 vs. 3.21±0.85, P=0.68). Furthermore, the CFR was significantly lower in uncontrolled group than that of the other two hypertension groups and was significantly lower in controlled group than that of ideally controlled group. Higher blood pressure (β=-0.17, P=0.03) and age(β=-0.02, P=0.03) were independent predictors of lower CFR in patients with hypertension.

CONCLUSIONS

Higher blood pressure is an independent predictor of decreased CFR in patients with hypertension. Hypertensive patients with ideally controlled blood pressure have similar CFR level as patients without hypertension.

[A case report of cerebral resuscitation by surface cooling in a patient with cardiac arrest]

Therapeutic hypothermia is an important treatment for cerebral resuscitation in patients after cardiac arrest. But it is rarely used for comatose survivor post-cardiac arrest in China. The patient was the first case who was in coma post cardiac arrest caused by acute myocardial infarction and given hypothermia therapy in our hospital. After coronary reperfusion and therapeutic hypothermia, the patient's sneurologic function was recovered to normal. The paper discussed the indications, contraindications, cooling methods and complications of therapeutic hypothermia.

[Effects of verticillatine on cerebral blood flow, cerebral vascular resistance and blood pressure in anesthetized dogs and cats]

The effects of verticillatine (Ver), hexamethonium (Hex) and nimodipine (Nim) on mean arterial pressure (MAP), cerebral blood flow (CBF) and cerebrovascular resistance (CVR) were determined in pentobarbital anesthetized animals using the method of electromagnetic flow meter in dogs and hydrogen clearance in cats. Ver or Nim iv induced significant reduction of MAP and CVR. CBF was increased in dogs and unaltered in cats. The Hex treated dogs and cats exhibited a fall of MAP and CBF with enhancement of CVR. In cats after middle cerebral artery occlusion (MCAO), regional cerebral blood flow (rCBF) was reduced from 190 +/- 70 to 90 +/- 20 ml.kg-1.min-1. Ver and Nim iv caused similar changes of MAP and CVR to those before MCAO. The results suggest that Ver and Nim may have vasodilation effect and improve the cerebral circulation. Thus, they would be beneficial to patients suffering from hypertension.

The influence of proglumide, a putative CCK antagonist, on cerebral ischemia in gerbil

Studies were conducted to clarify the possible role of CCK in cerebral ischemia and to evaluate the effects of proglumide, a competitive and reversible CCK antagonist, as a potential therapeutic or prophylactic tool in the treatment of cerebral ischemia. Proglumide at the doses of 10, 50 and 150 mg/kg was administered to gerbils before unilateral carotid ligation, and its effect on stroke index score, incidence and mortality rate was observed. Our results show that proglumide injected prior to carotid ligation at the dose of 150 mg/kg significantly reduces both incidence and mortality rate and changes the distribution of the stroke index score in gerbils. There was a significant inverse relationship between the dose of proglumide and both incidence and mortality: the greater the injection dose of proglumide, the lower the incidence and mortality. These results suggest that CCK may be involved in the pathological processes of cerebral ischemia and proglumide or related compounds prove to be effective in the pharmacological prophylaxis of ischemic brain damage.