OBJECTIVEPatient with myocardial bridging (MB) usually has a benign prognosis, but some MB patients might experience myocardial ischemia, infarction and sudden cardiac death, especially during active physical activities. The purpose of the study was to study the stress-induced blood flow changes of the mural coronary artery in MB patients determined by intracoronary Doppler.

METHODSIn 8 patients with MB, the basic average peak velocity (bAPV), hyperemic average peak velocity (hAPV) of blood flow, coronary flow reverse (CFR) proximal and distal to the mural coronary artery were measured before and during intravenously dobutamine (10 microg kg-1 min-1, then add 10 microg kg-1 min-1 at 3 min interval till 40 microg kg-1 min-1) by intracoronary Doppler.

RESULTSThe baseline mural coronary diameter reduction was (51.7+/-21.4)% and significantly increased to (90.0+/-12.7)% (P<0.01) during dobutamine infusion. bAPV on the segments proximal and distal to the mural coronary artery significantly increased from (19.83+/-5.84) cm/s and (20.75+/-4.91) cm/s to (31.52+/-10.93) cm/s and (30.46+/-9.01) cm/s (all P<0.05 vs. baseline) respectively post dobutamine infusion. CFR measured at proximal and distal to myocardial bridging also significantly decreased from (2.91+/-0.62) and (2.46+/-0.82) to (2.17+/-0.66) and (1.83+/-0.51) (all P<0.01).

CONCLUSIONStress can significantly increase the compression of intramural coronary artery and reduce CFR on coronary segments both proximal and distal to the MB. Thus, active exercise might induce myocardial ischemia in patients with myocardial bridging.

Blood Flow Velocity ; Cardiotonic Agents ; pharmacology ; Coronary Circulation ; drug effects ; Coronary Vessel Anomalies ; physiopathology ; Coronary Vessels ; drug effects ; Dobutamine ; pharmacology ; Female ; Humans ; Male ; Middle Aged

OBJECTIVETo evaluate the direct effects of dobutamine as compared to adenosine on the coronary microcirculation in both normal and stenotic segments using myocardial contrast echocardiography (MCE).

METHODSLeft anterior descending (LAD) coronary artery stenosis, which was not flow limiting at rest, was established in 9 dogs. At the baseline and during intracoronary infusion of dobutamine (2 mg.kg(-1).min(-1)) and adenosine (5 mg.kg(-1).min(-1)), the radiolabeled microsphere (RM)-derived myocardial blood flow (MBF) were determined, and the double product (DP) and myocardial vascular resistance (MVR) were calculated. MCE was performed to determine the myocardial blood volume (MBV, represented by A) and microbubble velocity (beta).

RESULTSAs compared to the baseline level, the MBF increased and MVR decreased significantly in both the normal and abnormal beds during infusion of both drugs (P<0.05). In the normal bed, adenosine had no effect on MBV, the decrease in MVR was the result of decreased arteriolar (plus venular) resistance, and the increase in MBF was predominately due to the increase in b (deltabeta/ deltaA=13.6). Dobutamine caused a 28% increase in MBV, responsible for 32% of the decrease in the total MVR, but the increase in MBF arose mainly from the increase in b (deltabeta/deltaA=5.9). In the abnormal bed, both the drugs caused a similar increase in MBF entirely by increasing b, and 14% and 15% of the increases in capillary resistance were associated with the capillary derecruitment during administration of dobutamine and adenosine, respectively.

CONCLUSIONThe direct effects of intracoronary dobutamine infusion on the coronary microcirculation are similar to that of adenosine, and the increase in MBF occurs mostly as the result of increased myocardial blood velocity.

Adenosine ; pharmacology ; Adrenergic beta-Agonists ; pharmacology ; Animals ; Blood Flow Velocity ; drug effects ; Coronary Circulation ; drug effects ; Coronary Stenosis ; diagnostic imaging ; Coronary Vessels ; diagnostic imaging ; Dobutamine ; pharmacology ; Dogs ; Echocardiography ; methods ; Microcirculation ; drug effects ; Vasodilator Agents ; pharmacology

BACKGROUNDMyocardial perfusion associates with clinical syndromes and prognosis. Adenosine could improve myocardial perfusion of acute myocardial infarction within 6 hours, but few data are available on late perfusion of myocardial infarction (MI). This study aimed at quantitatively evaluating the value of intracoronary adenosine improving myocardial perfusion in late reperfused MI with myocardial contrast echocardiography (MCE).

METHODSTwenty-six patients with anterior wall infarcts were divided randomly into 2 groups: adenosine group (n = 12) and normal saline group (n = 14). Their history of myocardial infarction was about 3 - 12 weeks. Adenosine or normal saline was given when the guiding wire crossed the lesion through percutaneous coronary intervention (PCI), then the balloon was dilated and stent (Cypher/Cypher select) was implanted at the lesion. Contrast pulse sequencing MCE with Sonovue contrast via the coronary route was done before PCI and 30 minutes after PCI. Video densitometry and contrast filled-blank area were calculated with the CUSQ off-line software. Heart function and cardiac events were followed up within 30 days.

RESULTSPerfusion in the segments of the criminal occlusive coronary artery in the adenosine group was better than that in the saline group (5.71 +/- 0.29 vs 4.95 +/- 1.22, P < 0.05). Ischemic myocardial segment was deminished significantly after PCI, but the meliorated area was bigger in the adenosine group than in the saline group ((1.56 +/- 0.60) cm(2) vs (1.02 +/- 0.56) cm(2), P < 0.05). The video densitometry in critical segments was also improved significantly in the adenosine group (5.53 +/- 0.36 vs 5.26 +/- 0.35, P < 0.05). Left ventricular ejection fraction (LVEF) was improved in all patients after PCI, but EF was not significant between the two groups ((67 +/- 6)% vs (62 +/- 7)%, P > 0.05). There was no in-hospital or 30-day major adverse cardiac event (MACE) in the adenosine group but 3 MACE in the saline group in 30 days after PCI.

CONCLUSIONSAdenosine could improve myocardial microvascular perfusion in the late reopening of an occluded infarct related artery (3 to 12 weeks after AMI) and clinical outcome in the follow-up period, and myocardial microvascular perfusion is a powerful predictor of clinical events.

Adenosine ; administration & dosage ; Coronary Angiography ; Coronary Circulation ; drug effects ; Echocardiography ; Female ; Follow-Up Studies ; Humans ; Male ; Middle Aged ; Myocardial Infarction ; drug therapy ; physiopathology ; Myocardial Reperfusion ; Ventricular Function, Left

OBJECTIVE: To observe the immediate effect and safety of Shexiang Tongxin dropping pills (, STDP) on patients with coronary slow flow (CSF), and furthermore, to explore new evidence for the use of Chinese medicine in treating ischemic chest pain. METHODS: Coronary angiography (CAG) with corrected thrombolysis in myocardial infarction (TIMI) frame count (CTFC) was applied (collected at 30 frames/s). The treatment group included 22 CSF patients, while the control group included 22 individuals with normal coronary flow. CSF patients were given 4 STDP through sublingual administration, and CAG was performed 5 min after the medication. The immediate blood flow frame count, blood pressure, and heart rate of patients before and after the use of STDP were compared. The liver and kidney functions of patients were examined before and after treatments. RESULTS: There was a significant difference in CTFC between groups (P<0.05). The average CTFC values of the vessels with slow blood flow in CSF patients were, respectively, 49.98 ± 10.01 and 40.42 ± 11.33 before and after the treatment with STDP, a 19.13% improvement. The CTFC values (frame/s) measured before and after treatment at the left anterior descending coronary artery, left circumflex artery, and right coronary artery were, respectively, 48.00 ± 13.32 and 41.80 ± 15.38, 59.00 ± 4.69 and 50.00 ± 9.04, and 51.90 ± 8.40 and 40.09 ± 10.46, giving 12.92%, 15.25%, and 22.76% improvements, respectively. The CTFC values of vessels with slow flow before treatment were significantly decreased after treatment (P<0.05). There were no apparent changes in the heart rate, blood pressure, or liver or kidney function of CSF patients after treatment with STDP (all P>0.05). CONCLUSIONS The immediate effect of STDP in treating CSF patients was apparent. This medication could significantly improve coronary flow without affecting blood pressure or heart rate. Our findings support the potential of Chinese medicine to treat ischemic chest pain.
Blood Pressure ; drug effects ; Coronary Circulation ; drug effects ; physiology ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Female ; Heart Rate ; drug effects ; Humans ; Kidney ; drug effects ; physiopathology ; Liver ; drug effects ; physiopathology ; Male ; Middle Aged ; No-Reflow Phenomenon ; drug therapy ; physiopathology

OBJECTIVETo observe the effects of oral administration of guanxin II decoction (GX II) on cardiovascular function, especially on the dynamics of coronary blood flow in healthy males.

METHODSChanges of heart rate, diastolic pressure, systolic pressure, left ventricular ejection fraction (LVEF), E peak, A peak, E/A value of mitral flow, diastolic peak velocity (Vmax) and diastolic flow velocity time integrals (VTI) of left anterior descending coronary artery (LAD) in 11 healthy male subjects were measured before and after oral administration of GX II, using non-invasive echocardiogram.

RESULTSCompared with those before GX II administration, the changes after administration in heart rate, systolic pressure, diastolic pressure, LVEF, E peak, A peak and E/A value, were insignificantly different (P>0.05), but the Vmax and VTI significantly increased at 30 min, 60 min, 90 min and 120 min after GX II administration (P<0.05).

CONCLUSIONTo increase the coronary blood flow is possibly one of the mechanisms of GX II in treating coronary heart disease and angina pectoris.

Adolescent ; Adult ; Blood Flow Velocity ; drug effects ; Coronary Circulation ; drug effects ; Coronary Disease ; drug therapy ; Coronary Vessels ; drug effects ; ultrastructure ; Diastole ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; Echocardiography ; Heart Rate ; drug effects ; Humans ; Male ; Middle Aged ; Systole ; drug effects ; Vasodilator Agents ; pharmacology ; Ventricular Function, Left ; drug effects

BACKGROUNDReal-time perfusion imaging (RTPI) using ultrasound contrast agents has shown good "accuracy" in detecting myocardial infarction, however its accuracy in the assessment of peri-infarct ischemia and stress echocardiography are not known. The aim of this study was to determine the accuracy of RTPI in assessment of peri-infarct ischemia during dobutamine and adenosine stress.

METHODSWe employed the RTPI modality (Agilent and ATL Philips) in a canine model (18 dogs) of distal coronary occlusion and proximal coronary stenosis. Using coronary flow probe recordings, the physiologic significance of proximal coronary stenosis was established by confirming abolition of the coronary reserve. The contrast agent Optison was given as a slow bolus injection at baseline, during prolonged distal coronary occlusion, during adenosine bolus stress and during dobutamine stress. Triphenyltetrazolium chloride (TTC) staining was used to verify a distal infarction. RTPI recordings at baseline, the distal coronary occlusion and stress protocols were randomly mixed and reviewed blindly.

RESULTSIn all but one dog, RTPI detected a distal infarct as small as 9% of the left ventricle. The sensitivity, specificity and overall diagnostic accuracy of RTPI in the detection of distal infarcts were: 94%, 89% and 92%, respectively. The sensitivity, specificity, and overall diagnostic accuracy of RTPI in the assessment of peri-infarction ischemia were 83%, 92% and 88% for adenosine stress and 95%, 86% and 91% for dobutamine stress, respectively.

CONCLUSIONSEven small distal infarcts can be detected by RTPI; peri-infarct ischemia can be accurately recognized by RTPI during stress; adenosine and dobutamine stress appear equally reliable in the RTPI evaluation of peri-infarct ischemia.

Adenosine ; toxicity ; Animals ; Coronary Circulation ; drug effects ; Dobutamine ; toxicity ; Dogs ; Echocardiography ; methods ; Female ; Hemodynamics ; drug effects ; Male ; Myocardial Infarction ; diagnostic imaging

OBJECTIVETo evaluate the effect of treatment with Qishen Yiqi Dripping Pills (, QSYQ) on myocardial injury and myocardial microvascular function in patients undergoing elective percutaneous coronary intervention (PCI).

METHODSEighty patients undergoing elective PCI were randomly assigned to QSYQ and control groups. The QSYQ group received QSYQ at a dosage of 0.5 g 3 times daily (3-7 days before PCI and then daily for 1 month) and regular medication, which comprised of aspirin, clopidogrel, statin, β-blocker, and angiotensin-converting enzyme inhibitor/angiotensin receptor blocker in the absence of contradiction. The control group received only the regular medication. The index of microcirculatory resistance (IMR) was measured at maximal hyperemia after PCI. The fractional flow reserve was measured before and after the procedure. Troponin I levels were obtained at baseline and 20-24 h after the procedure.

RESULTSPre-PCI troponin I levels between the two groups were similar (0.028±0.05 vs. 0.022±0.04 ng/mL, P=0.55). However, post- PCI troponin I levels in the QSYQ group were significantly lower than that in the control group (0.11±0.02 vs. 0.16±0.09 ng/mL, P<0.01). IMR values were significantly lower in the QSYQ group as compared to the control group (16.5±6.1 vs. 31.2±16.0, P<0.01). Multivariate analysis identified QSYQ treatment as the only independent protective factor against IMR >32 (odds ratio=0.29, 95% confidence interval: 0.11-0.74, P=0.01).

CONCLUSIONSThe present study demonstrated the benefit of QSYQ in reducing myocardial injury and preserving microvascular function during elective PCI.

Aged ; Coronary Angiography ; Coronary Circulation ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Female ; Humans ; Male ; Microvessels ; diagnostic imaging ; drug effects ; physiopathology ; Middle Aged ; Multivariate Analysis ; Myocardium ; pathology ; Percutaneous Coronary Intervention ; Pilot Projects ; Troponin I ; blood

OBJECTIVETo assess the effect of beta blocker on blood flow velocity and reserve on the intramural coronary artery of patients with myocardial bridging.

METHODSIn 8 patients with myocardial bridge, intracoronary Doppler was performed before and after esmolol was given intravenously. The basic average peak velocity (bAPV), hyperaemic average peak velocity (hAPV) of blood flow, and coronary flow reserve (CFR) proximal and distal to the mural myocardial bridging was measured and compared.

RESULTSAfter esmolol injection, the mural coronary diameter systolic reduction decreased from (58.0 +/- 14.7)% to (26.0 +/- 9.8)% (P < 0.01); the bAPV proximal and distal to myocardial bridging separately decreased from (19.4 +/- 4.9) cm/s and (18.4 +/- 3.6) cm/s to (4.7 +/- 3.9) cm/s (P < 0.01) and (15.1 +/- 1.5) cm/s (P < 0.05). Under hyperemization, esmolol changed the hAPV of proximal and distal to myocardial bridging separately from (54.1 +/- 14.9) cm/s and (44.7 +/- 9.4) cm/s to (49.7 +/- 16.4) cm/s and (48.9 +/- 10.1) cm/s (all P > 0.05); thus, the value of CFR both proximal and distal to myocardial bridge increased separately from 2.8 +/- 0.3 and 2.5 +/- 0.5 to 3.4 +/- 0.5 and 3.2 +/- 0.6 (all P < 0.01).

CONCLUSIONEsmolol can decreased the compression of the intramural coronary artery and increased the CFR to normal level of it.

Adrenergic beta-Antagonists ; pharmacology ; therapeutic use ; Coronary Circulation ; drug effects ; physiology ; Coronary Vessels ; diagnostic imaging ; drug effects ; physiopathology ; Female ; Humans ; Male ; Middle Aged ; Myocardial Bridging ; drug therapy ; physiopathology ; ultrastructure ; Propanolamines ; pharmacology ; therapeutic use ; Ultrasonography, Interventional

Nicardipine is a potent coronary and systemic vasodilator without depression of ventricular function. We investigated the changes in local myocardial perfusion (LMP) according to the nicardipine administration after coronary reperfusion in a beating canine model. A Doppler probe was placed around the left anterior descending coronary artery (LAD) and thermal diffusion microprobe was implanted in the myocardium perfused by the exposed LAD. To define the nicardipine effects, we compared the two groups (control group, n=7 vs nicardipine group, n=7). In nicardipine group, 5 microgram/kg/min nicardipine was infused continuously. After the release of the LAD occlusion, LAD blood flow were increased compared to the baseline of both groups. However, there was no difference between groups in the LAD blood flow. The LMP after LAD reperfusion did not recover to the baseline level until 30 min after LAD reperfusion in control group (74%, 52% and 70% at 10, 20 and 30 min after LAD reperfusion, respectively). In nicardipine group, however, the LMP recovered to the baseline level at 20 min (99%), and increased more than the baseline level at 30 min (141%) after LAD reperfusion. Our findings suggest that the nicardipine augments the LMP following the release of a coronary occlusion.
Animals ; Coronary Circulation/drug effects* ; Dogs ; Drug Evaluation, Preclinical ; Myocardial Reperfusion* ; Myocardial Reperfusion Injury/prevention & control* ; Nicardipine/pharmacology* ; Nicardipine/therapeutic use ; Vasodilator Agents/pharmacology* ; Vasodilator Agents/therapeutic use

OBJECTIVETo assess the effect of Tongxinluo (TXL) ultramicro-pulverization in preventing and treating post-reperfusion no-reflow in mini-swine model of acute myocardial infarction.

METHODSForty mini-swines were randomly divided into 5 groups, the control group, the three (low-, middle- and high-dose) TXL groups and the sham-operation group, with 8 in each group. After pigs in the three TXL groups were administered with TXL in a dose of 0.05g/kg, 0.2g/kg and 0.5g/kg once a day for 3 days respectively, they were made into acute myocardial ischemia/reperfusion model by ligating left anterior descending coronary artery for 3h followed with 1h of untying. Hemodynamic examination and myocardial contrast echocardiography (MCE) were conducted before and after ligation, and after reperfusion, finally, pathological analysis was done.

RESULTSPost-reperfusion ventricular function injury was significantly improved in the three TXL groups, as compared with the control group, the no-reflow area determined by hemodynamic and MCE decreased from 78.5 +/- 4.4% and 82.3 +/- 1.9% in control to 43.4 +/- 3.2% and 44.6 +/- 3.3% (low-dose), 25.2 +/- 2.4% and 25.7 +/- 4.0% (middle-dose), 24.0 +/- 1.9% and 24.9 +/- 4.2% (high-dose), respectively (P < 0.05 or P < 0.01), and the myocardial infracted area was reduced from 98.5 +/- 1.4% to 89.8 +/- 4.6%, 80.2 +/- 3.1% and 79.9 +/- 3.1%, respectively (P < 0.05, P < 0.01).

CONCLUSIONTXL ultramicro-pulverization can effectively prevent and treat no-reflow after myocardial acute infarction following reperfusion, and reduce the infracted area.

Animals ; Coronary Circulation ; drug effects ; Drugs, Chinese Herbal ; therapeutic use ; Female ; Male ; Myocardial Infarction ; drug therapy ; Myocardial Reperfusion Injury ; prevention & control ; Phytotherapy ; Powders ; Random Allocation ; Swine ; Swine, Miniature