Use of intra-aortic nitroglycerin in the cardiac catheterization laboratory

The purpose of this study was to determine whether nitroglycerin (NTG) injected into the ascending aorta or left ventricle would safely and effectively lower blood pressure in hypertensive patients undergoing cardiac catheterization. Fifty bolus injections of 297 ± 67 μg (mean ± SD) NTG were given to patients with a systolic blood pressure (SBP) of ?140 mm Hg (mean SBP 188 ± 20.1 mm Hg). An average drop in systolic blood pressure of 36 ± 16 mmHg (P < 0.001), diastolic blood pressure of 19 ± 7 mm Hg (P < 0.001), and left ventricular end-diastolic pressure of 4.7 ± 4 mm Hg (P = 0.001) was well tolerated in each patient. The mean time to response was 11 ± 3 sec. Intra-aortic injection of NTG is a safe and effective means to treat hypertensive patients in the cardiac catheterization laboratory. © 1995 Wiley-Liss, Inc.     

Relief of coronary artery spasm by nitroglycerin: Time-dependent variability in drug action

The arteriographic distinction between a fixed atheromatous obstruction and localized vasospasm in the coronary artery is often decided by the response of the lesion to nitroglycerin. We studied the time course of nitroglycerin in four patients with coronary artery spasm as revealed by selective angiography. Following complete dissolution of a 0.6 mg tablet of nitroglycerin sublingually, a slight increase in heart rate occurred as early as two minutes, variable changes in overall vessel diameter were observed within four minutes, but the localized spasm remained fixed. It was not until six minutes had elasped that reinjection showed disappearance of spasm and uniform patency of the vessel in all cases. These observations stress the importance of waiting an appropriate period of time (at least six minutes) following complete absorption of sublingual nitroglycerin before any conclusion can be rationally drawn regarding the nature of a stenotic lesion as seen angiographically.     

血流储备分数测定中最大充血相诱发药物的应用

血流储备分数作为冠状动脉狭窄功能性评价的指标已广泛应用于临床。在血流储备分数的测定中必须用药物来诱发最大充血相。现就血流储备分数的测定中所用的最大充血相诱发药物进行综述,讨论各种药物的特点及这方面药物的一些进展。     

Chronic oral vasodilator therapy to control heart failure in postinfarction ventricular septal defect

This report describes a 70-year-old woman with biventricular failure following an anteroseptal infarction complicated by interventricular septal rupture. Treatment with nitroprusside followed by oral hydralazine eliminated the failure and reduced the shunt from 2.75 to 1 to 1.7 to 1. She is asymptomatic post-discharge. Chronic medical therapy including oral vasodilators may be an acceptable alternative to surgery in a small minority of patients with this complication of myocardial infarction.     

Relation of vasodilator response of the brachial artery to inflammatory markers in patients with coronary artery disease

Endothelial dysfunction of the coronary artery is closely related to elevated levels of systemic inflammatory markers and cardiovascular events in patients with coronary artery disease (CAD). We hypothesized that patients with CAD may have a higher risk of endothelial dysfunction of the peripheral artery than patients without evidence of CAD, and that endothelial dysfunction of the peripheral artery also may be related to elevated levels of inflammatory markers. Using high resolution ultrasound, we assessed the brachial vasodilator response to reactive hyperemia (endothelium-dependent) and sublingual nitroglycerin (endothelium-independent). As inflammatory markers, serum C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) levels, and lipid profiles were measured in patients with CAD (n = 30, 16 male and 14 female) and normal subjects without evidence of CAD (n = 45, 23 male and 22 female). Patients with CAD (Group II) showed a significantly reduced endothelium-dependent vasodilation as compared with normal subjects (Group I) (4.4 +/- 3.6 vs 7.4 +/- 6.1%, P < 0.05). However, endothelium-independent vasodilation was not significantly different between the two groups (7.7 +/- 7.1 vs 9.7 +/- 8.0%, P > 0.05). In Group II, CRP level was inversely related to endothelium-dependent vasodilation (r = -0.398, P = 0.029). In contrast, ESR level was not significantly associated to endothelium-dependent vasodilation (r = -0.113, P = 0.552). On multivariate analysis, CRP and low density lipoprotein cholesterol levels were significant independent predictors of a blunted endothelium-dependent vasodilation in Group II. Our study showed that elevated CRP level was associated with blunted endothelium-dependent vasodilation of the brachial artery in patients with CAD. Thus, identification of elevated CRP levels combined with demonstration of endothelial dysfunction of the brachial artery may have a possible clinical application for the detection of high risk CAD patients.     

Aortic input impedance in heart failure: comparison with normal subjects and its changes during vasodilator therapy

This study was aimed at the evaluation of aortic impedance inpatients with congestive heart failure. Aortic impedance (simultaneousmeasurements of aortic pressure and blood flow), mean (W_m) andpulsatile (W_p) powers were compared in 11 normal subjects andin 12 patients with heart failure. Pulse wave velocity (C: modifiedMoens-Korteweg equation, simultaneous measurements of aorticpressure and radius) was determined under control conditionsin all normal subjects and in 7 patients with heart failure.Impedance curves in patients with heart failure were characterizedby increased values of the impedance modulus at 0 Hz (peripheralresistance) and at low frequencies. The characteristic impedance,C, and phase were not different from normal subjects. In sixpatients with heart failure, impedance curves were studied duringnitroprusside infusion. During the infusion of the vasodilator,the impedance modulus at 0 Hz and at low frequencies decreased.The characteristic impedance was unchanged. The zero interceptof the phase was shifted towards lower frequencies. These resultsshow that the changes in impedance curves in patients with heartfailure are due to greater peripheral resistance and wave reflection.During nitroprusside infusion the stroke volume increased andthe aortic blood flow became more pulsatile (greater valuesof low frequency components). This modification accounts forthe increased values ofW_m and W_p, and is related to decreasedperipheral resistance and wave reflection.     

两种血管升压药物治疗婴幼儿复杂心脏手术后血管舒张性休克的疗效比较

目的：比较血管加压素（AVP）和去甲肾上腺素（NE）对婴幼儿复杂先天性心脏病手术后血管舒张性休克患者的疗效。方法：回顾性总结2010年6月~2012年10月32例心脏术后早期使用小剂量AVP的复杂婴幼儿心脏手术患者（试药组）,与2008年8月~2010年5月实施的另外35例早期使用去甲肾上腺素（NE）的复杂婴幼儿心脏手术患者（对照组）的临床资料进行比较。结果：两组患者基本资料、心率、血压、中心静脉压、最高乳酸值、最低中心静脉血氧饱和度（ScvO2）、静动脉二氧化碳分压差（Pcv-aCO2） 、尿量、胸引量组间差异不显著 ;AVP组血管活性药物评分更低、心率失常发生率更低、呼吸机辅助时间及住监护室时间减少。结论：AVP改善体外循环下术后血管舒张性休克患者的疗效优于NE。     

Piroximone, dobutamine and nitroprusside: comparative effects on haemodynamics in patients with congestive heart failure

Four intravenous doses of piroximone, an imidazolone derivative, were administered to 12 patients with congestive heart failure to produce a four-point dose-response curve. The haemodynamic effects were compared with those of dobutamine and nitroprusside, the substances being given sequentially and in randomized order. Piroximone and dobutamine significantly and similarly increased cardiac index (CI) and stroke volume index (SVI). Nitroprusside produced no such effect. By contrast, piroximone and nitroprusside significantly and similarly decreased mean pulmonary artery pressure (MPAP), pulmonary capillary wedge pressure (PCWP), right atrial pressure (RAP) and pulmonary vascular resistance (PVR), while such changes were not seen following dobutamine. Direct comparisons between the agents were made at doses that lowered systemic vascular resistance (SVR) to the same extent. The major difference between dobutamine and piroximone was an apparent additional vasodilator activity displayed by piroximone as demonstrated by a significantly greater decrease in MPAP, PCWP and RAP for a matched reduction in SVR and a similar increase in CI. The major difference between nitroprusside and piroximone was the significantly higher increase in CI and SVI elicited by piroximone for a matched reduction in SVR and a similar decrease in PCWP and RAP. The changes in loading conditions being equivalent, the higher increase in CI is likely to be accounted for by a direct inotropic activity.     

Evaluation of a spasmolytic cocktail to prevent radial artery spasm during coronary procedures.

Radial artery spasm is a frequent complication of the transradial approach for coronary angiography and angioplasty. Recently, we have been able to quantify spasm using the automatic pullback device. The objective of this study was to assess the efficacy of an intra-arterial vasodilating cocktail in reducing the incidence and severity of radial artery spasm. A hundred patients undergoing coronary procedures via the radial artery were divided into two groups of 50 each. Patients in group A received intra-arterial cocktail (5 mg of verapamil plus 200 micro g nitroglycerine in 10 ml of normal saline), while patients in group B did not receive any vasodilating drug. The pullback device was used for sheath removal at the end of the procedure. Seven (14%) patients in group A experienced pain (i.e., pain score of III-V) during automatic sheath removal, as compared to 17 (34%) in group B (P = 0.019). The mean pain score was significantly lower in group A than in group B (1.7 +/- 0.94 vs. 2.08 +/- 1.07; P = 0.03). The maximal pullback force (MPF) was also significantly lower for group A (0.53 +/- 0.52 kg; range, 0.10-3.03 kg) as compared to group B (0.76 +/- 0.45 kg; range, 0.24-1.99 kg; P = 0.013). Only 4 (8%) patients in group A had an MPF value greater than 1.0 kg, suggesting the presence of significant radial artery spasm, as opposed to 11 (22%) in group B (P = 0.029). Administration of an intra-arterial vasodilating cocktail prior to sheath insertion reduces the occurrence and severity of radial artery spasm.     

Carotid-radial pulse wave velocity responses following hyperemia in patients with congestive heart failure

Carotid-radial pulse wave velocity (PWV) normally decreases following hyperemia and is an indicator of vasodilator reserve. This response is impaired in patients with congestive heart failure (CHF). To identify specific factors related to an impaired response, we studied 50 patients (60 ± 14 years, 67% male) with chronic CHF. Baseline PWV was measured using applanation tonometry and repeated 1 minute after release of upper arm occlusion for 5 minutes. Percentage changes (Δ) of PWV were normally distributed and mean ΔPWV was −2.2 ± 15.3%. On univariate analyses, ΔPWV correlated with New York Heart Association class, mean arterial pressure, log brain natriuretic peptide (BNP) levels, and baseline PWV, but not with left ventricular ejection fraction. Multivariate linear regression analysis demonstrated log BNP levels, mean arterial pressure, and baseline PWV (all P < .05) as independent predictors of ΔPWV. Hyperemia increased PWV in 42% of patients. On logistic regression, higher BNP levels and lower baseline PWV were independent predictors of a PWV increase. Higher BNP levels and lower baseline PWV are independent predictors of an abnormal hyperemic PWV response in patients with CHF. Higher BNP levels may reflect abnormal vasodilator reserve. Forty-two percent of heart failure patients showed an increase in PWV following hyperemia, which may reflect more severe arterial vasodilator impairment.     

Worsening of coronary spasm during the perioperative period:A case report

We present the case of a 65-year-old male with vasospastic angina(VSA)whose condition worsened during the perioperative period.He had been diagnosed with VSA 10 years prior.He was treated with two types of vasodilators and had not experienced any chest symptoms for 5 years.At this juncture,he underwent surgery for relapsed maxillary sublingual carcinoma.He had taken two vasodilators one day prior to surgery.Intravenous infusion of nitroglycerin(NTG)was initiated immediately before the surgery and continued the following day.Instead of stopping NTG,a dermal isosorbide dinitrate tape was applied on post-operative day 1.Two days later,a complete atrioventricular block with pulseless electrical activity appeared.After cardiopulmonary resuscitation,emergent coronary angiography showed severe coronary spasm in both the left and right coronary arteries.Intracoronary infusion of nitroglycerin and epinephrine with percutaneous cardiopulmonary support relieved the coronary spasm.During the perioperative period,several factors can trigger coronary vasospasm,including the discontinuation of vasodilators.Thus,surgeons,anesthetists,and cardiologists should watch for coronary vasospasm during this period and for worsening coronary spasm when discontinuing vasodilators in patients at risk for VSA.     

Improvement of exercise capacity after nifedipine in patients with Eisenmenger syndrome complicating ventricular septal defect.

We investigated the potential benefit of a preferential pulmonary vasodilatory effect of nifedipine in 4 patients with Eisenmenger syndrome complicating ventricular septal defect. First-pass radionuclide scan was performed at rest to measure intracardiac shunting before and after nifedipine. Two hours after 20 mg sublingual nifedipine, right-to-left shunt increased from 16.3 +/- 1.4 to 20.4 +/- 1.5% (p less than 0.05), but systemic arterial oxygen saturation (SAO2) remained steady. With 4 weeks of maintenance nifedipine therapy, resting intracardiac shunting and SAO2 were unchanged from baseline. Symptom-limited cycle ergometry was performed before and after maintenance nifedipine with placebo control. Exercise duration was prolonged (8.7 +/- 0.6 vs. 6.8 +/- 0.9 min; p less than 0.02) and SAO2 at each stage of exercise was consistently increased in all patients after nifedipine. Cardiac output and the SAO2 at peak exercise were similar. Thus, chronic nifedipine therapy increases SAO2 on exercise and improves maximal exercise capacity in patients with Eisenmenger syndrome, which is not predicted by study of resting intracardiac shunting after acute therapy.     

The Antihypertensive Effect of Pinacidil versus Prazosin in Mild to Moderate Hypertensive Patients Seen in General Practice

Abstract. The antihypertensive effect of a new vasodilating drug, pinacidil, was compared with prazosin in a randomized, open study in general practice including 131 patients with a sitting diastolic blood pressure (DBP) between 100–115 mmHg. At inclusion 108 patients were untreated and the remaining patients were on treatment with thiazide diuretics and/or β-blockers. The aim was to reduce the sitting DBP to ≤95 mmHg, which was achieved in 85% of the patients treated with pinacidil and in 77% of the patients treated with prazosin (NS). In the responding patients the reductions were (mean±SD) 16±7 mmHg (p<0.001) and 13±6 mmHg (p<0.001) in the pinacidil group (n=60) and the prazosin group (n=46), respectively (p<0.10). During 5 months of maintenance therapy no statistically significant differences in blood pressures between the two treatment groups were present. Side-effects were typical of vasodilator therapy, i.e. headache, dizziness, tachycardia and edema, leading to discontinuation of therapy in 10 patients in each treatment group. Heart rate (HR) was increased with pinacidil and unchanged with prazosin. Edema was frequently seen with pinacidil and dizziness with prazosin. Because of edema a thiazide diuretic was given to nine patients in the pinacidil group and two patients in the prazosin group. No clinically significant changes in ECG and biochemical variables were observed. In conclusion, the study has demonstrated that pinacidil is as effective an antihypertensive agent as prazosin. Pinacidil may be used as monotherapy. However, the study suggests that pinacidil should be used as add-on therapy to thiazide diuretics.     

Intravenous fenoldopam infusion in severe heart failure

Summary Fenoldopam, a selective DA₁-receptor agonist, infused intravenously for 24 hours (0.6 ± 0.3 µg/kg/min, range 0.1–1.5) in 25 patients with NYHA functional class III or IV heart failure, produced a prompt and sustained hemodynamic response. Cardiac index rose from an average preinfusion baseline value of 1.8 to 2.6/l min. Stroke volume index increased from 19 to 26 ml/m² and stroke work index increased from 18 to 25 g M/m². These changes were accompanied by a reduction in systemic vascular resistance from an average of 2400 to 1500 dynes sec/cm.⁵ There was no change in the heart rate or right atrial pressure. There was a transient reduction in the left ventricular filling pressure from 25 to 20 mmHg. Urinary sodium excretion did not change significantly. Transient asymptomatic thrombocytopenia developed in four patients. The drug was well tolerated by all patients. These results suggest that continuous intravenous infusion of fenoldopam is safe and produces favorable hemodynamic responses in severe heart failure. However, unlike its effects in patients with hypertension, it failed to produce sustained natriuresis in these patients.