多巴酚丁胺 硝酸甘油 酚妥拉明治疗顽固性心力衰竭38例分析

目的 观察多巴酚丁胺、硝酸甘油、酚妥拉明对顽固性心衰（RHF）患者的疗效。方法 静脉点滴多巴酚丁胺、硝酸甘油、酚妥拉明治疗RHF患者38例,观察其临床疗效及治疗前后临床指标的变化。结果 心功能改善Ⅱ级20例（占52．6％）,改善Ⅰ级（占42．1％）,总有效率为94．7％。用药后心率、血压、呼吸明显好转,X线心胸比率、腹围、BUN、MOC明显下降,尿量明显增多（P值均＜0．01）,未见不良反应。结论 多巴酚丁胺、硝酸甘油、酚妥拉明治疗RHF安全有效。     

多巴酚丁胺负荷超声心动图中血流动力学变化对冠心病预后评价的意义

目的　探讨多巴酚丁胺负荷超声心动图 (DSE)中血流动力学变化对冠心病预后评价的意义。方法　用DSE方法观察 2 8例正常人 (A组 )和 80例冠心病 (CAD)病人 (B组 )血流动力学变化 ,通过长期随访 ,比较 2组的预后与血流动力学变化的关系。结果　随访 10 8例 ,B组共发生心脏事件 33例 ,其中硬性事件 14例 ,软性事件19例 ,而A组无心脏事件发生。A、B两组免于事件的累积生存率有显著性差异 (P <0 .0 1)。B组中发生心脏事件者 (BⅠ亚组 )与未发生心脏事件者 (BⅡ亚组 )血流动力学指标具有明显差异 (P <0 .0 1)。B组中最大负荷时收缩压 /收缩末期容积指数 (SBP/ESVI)正常者与低于正常值范围者累积生存率具有显著性差异 (P <0 0 1)。结论DSE期间诱发心肌缺血的因素如SBP/ESVI、室壁应力增加 ,外周血管阻力指数 (TVRI)轻度下降 ,HR、SBP、RPP增加等可以提供CAD病人发生心脏事件的预测信息 ,尤其是B组中最大负荷时SBP/ESVI低于正常值范围者 ,对于判断预后具有重要意义。     

多巴酚丁胺负荷心肌声学造影探测冠状动脉狭窄

目的 评价多巴酚丁胺负荷心肌声学造影（MCE）诊断冠脉狭窄的准确性。方法 在慢性冠脉狭窄闭胸犬模型上同步进行MCE和放射性微球测定心肌血流量（MBF）。结果 负荷状态时,异常冠脉供血区（MBF储备<3）呈现灌注缺损,峰值声强度（VI）较正常冠脉供血区低（33±13与48±14,P<0.01）,且异常和正常冠脉供血区峰值VI比值与相应MBF比值呈良好的线性正相关（r=0.86,P<0.0001）。结论 多巴酚丁胺可作为一种负荷药物用于MCE评价冠脉狭窄。     

Relation between myocardial response to dobutamine stress and sympathetic nerve activation in patients with idiopathic dilated cardiomyopathy: A comparison of123I-MIBG scintigraphic and echocardiographic data

It is likely that a close association exists between findings obtained by two methods: dobutamine stress echocardiography and 123I-MIBG scintigraphy. Both of these methods are associated with beta-adrenergic receptor mechanisms. This study was conducted to demonstrate the relation between myocardial response to dobutamine stress and sympathetic nerve release of norepinephrine in the failing heart. In 12 patients with heart failure due to idiopathic dilated cardiomyopathy, the myocardial effects of dobutamine stress were evaluated by low-dose dobutamine stress echocardiography: and sympathetic nerve function was evaluated by scintigraphic imaging with iodine-123 [123I] meta-iodobenzylguanidine (MIBG), an analogue of norepinephrine. Echocardiography provided quantitative assessment of wall motion and left ventricular dilation; radiotracer studies with 123I-MIBG provided quantitative assessment of the heart-to-mediastinum (H/M) uptake ratio and washout rate. Results showed that H/M correlated with baseline wall motion (r = 0.682, p = 0.0146), wall motion after dobutamine stress (r = 0.758, p = 0.0043), the change in wall motion (r = 0.667, p = 0.0178), and with left ventricular diastolic diameter (r = 0.837, p = 0.0007). In addition, the 123I-MIBG washout rate correlated with baseline wall motion (r = 0.608, p = 0.0360), wall motion after dobutamine stress (r = 0.703, p = 0.0107), and with the change in wall motion (r = 0.664, p = 0.0185). Wall motion, especially in the myocardial response to dobutamine stress, is related to sympathetic nerve activity in heart failure.     

In vivo investigation of cardiac metabolism in the rat using MRS of hyperpolarized [1‐13C] and [2‐13C]pyruvate

Hyperpolarized ¹³C MRS allows the in vivo assessment of pyruvate dehydrogenase complex (PDC) flux, which converts pyruvate to acetyl‐coenzyme A (acetyl‐CoA). [1‐¹³C]pyruvate has been used to measure changes in cardiac PDC flux, with demonstrated increase in ¹³C‐bicarbonate production after dichloroacetate (DCA) administration. With [1‐¹³C]pyruvate, the ¹³C label is released as ¹³CO₂/¹³C‐bicarbonate, and, hence, does not allow us to follow the fate of acetyl‐CoA. Pyruvate labeled in the C₂ position has been used to track the ¹³C label into the TCA (tricarboxylic acid) cycle and measure [5‐¹³C]glutamate as well as study changes in [1‐¹³C]acetylcarnitine with DCA and dobutamine. This work investigates changes in the metabolic fate of acetyl‐CoA in response to metabolic interventions of DCA‐induced increased PDC flux in the fed and fasted state, and increased cardiac workload with dobutamine in vivo in rat heart at two different pyruvate doses. DCA led to a modest increase in the ¹³C labeling of [5‐¹³C]glutamate, and a considerable increase in [1‐¹³C]acetylcarnitine and [1,3‐¹³C]acetoacetate peaks. Dobutamine resulted in an increased labeling of [2‐¹³C]lactate, [2‐¹³C]alanine and [5‐¹³C]glutamate. The change in glutamate with dobutamine was observed using a high pyruvate dose but not with a low dose. The relative changes in the different metabolic products provide information about the relationship between PDC‐mediated oxidation of pyruvate and its subsequent incorporation into the TCA cycle compared with other metabolic pathways. Using a high dose of pyruvate may provide an improved ability to observe changes in glutamate. Copyright © 2013 John Wiley & Sons, Ltd.     

The Role of Optical Coherence Tomography in Clarifying the Mechanisms for Dobutamine Stress Echocardiography‐Induced Takotsubo Cardiomyopathy

Takotsubo cardiomyopathy is a clinical disorder characterized by a transient dilatation and akynesis or dyskinesis of the left ventricular (LV) apex, mimicking an anterior wall acute myocardial infarction in the absence of significant coronary artery disease (CAD). It typically occurs during an episode of severe emotional or physical stress. Recent reports suggested the potential of dobutamine stress echocardiography (DSE) in inducing the aforementioned syndrome. The transient dysfunction of the LV does not fit any known coronary distribution. Furthermore, there is no obstructive CAD demonstrated at angiography to account for the observed dysfunction. Consequently, the pathophysiology of this syndrome is still undetermined. Here, we report a case of DSE‐induced Takotsubo cardiomyopathy in which high‐resolution intracoronary imaging was utilized to exclude possible vessel alterations to help provide potential mechanistic explanations for the development of this condition.     

Vulnerability to Sympathetic Stress Does Not Persist in Takotsubo Stress Cardiomyopathy

ObjectiveOur objective was to investigate whether dobutamine stress echocardiography (DSE) could induce abnormal cardiac function in takotsubo stress cardiomyopathy (TSC) patients in a stable condition after the acute attack.Methods and ResultsThis was a case-control study and a substudy of the Stockholm Myocardial Infarction With Normal Coronaries (SMINC) study. Twenty-two patients with a previous episode of TSC and 22 sex- and age-matched control subjects were recruited from the SMINC study and investigated with the use of DSE. All TSC patients had a previous normal cardiovascular magnetic resonance investigation. Tissue Doppler imaging–derived time phases of the cardiac cycle were recorded to calculate myocardial performance index (MPI) to assess ventricular function. Compared with control subjects at rest, TSC patients had a slightly but significantly higher left ventricular MPI (LV-MPI; 0.53 vs 0.59; P = .01) and as a trend higher right ventricular MPI (0.38 vs 0.47; P = .08), although during DSE these variables did not differ significantly.ConclusionWe found no difference in standard diastolic parameters between TSC and control subjects, but a significant higher value in LV-MPI in the TSC group at rest. However, no such difference could be demonstrated during DSE between the groups, indicating that vulnerability to sympathetic stimulation does not persist in TSC patients.