TCD evaluation before and after stenting in patients with severe primary carotid artery stenosis versus restenosis.

PURPOSE: To evaluate cerebral hemodynamics before and after carotid angioplasty and stenting (CAS) using transcranial Doppler (TCD). METHODS: Sixty-eight patients (52 men; mean age 69+/-9.5 years) with severe carotid stenosis (83.4%+/-10.2%) were examined by TCD before and 2 months after CAS. Thirty-two (47%) patients had primary carotid stenosis and 36 (53%) had restenosis after carotid endarterectomy (CEA). A broad TCD protocol was employed to estimate cerebral hemodynamics, including assessment of velocities (V) and asymmetry of cerebral blood flow velocity (CBFV) in the middle cerebral artery, (MCA) anterior cerebral artery (ACA), and basilar artery (BA); the pulsatility indexes; and flow acceleration. RESULTS: Ipsilateral MCA mean velocities before stenting were 46.3+/-12.6 cm/s in the primary stenosis group and 47.1+/-12.3 cm/s in restenosis group; after stenting, the velocities were 53.8+/-12.1 and 52.7+/-9.6 cm/s, respectively (p<0.005 for both groups). MCA asymmetry by Vmean before CAS was higher in the primary stenosis group (27.6%+/-2.4% versus 19.8%+/-2.3%, p<0.05). After stenting, this index was significantly lower in both groups: 16.4%+/-2.4% and 12.3%+/-2.3%, respectively (p<0.0001 for each group). All other TCD parameters improved significantly in both groups after CAS as well (p<0.05), showing the strong hemodynamic effect of this procedure. CONCLUSION: CAS effectively improves cerebral hemodynamics in patients with severe primary and restenosis of the internal carotid artery.     

Systemic blood pressure and cerebral blood flow velocity during carotid surgery

BACKGROUND: To evaluate the effect of mean arterial blood pressure (MAP) on cerebral perfusion during carotid surgery, we investigated blood flow velocity in the middle cerebral (Vs,mca) using transcranial Doppler ultrasonography (TCD). METHODS: During carotid crossclamping, treatment included either phenylephrine-induced hypertension without shunting (Group XC; n = 11) or insertion of a shunt (Group S; n = 12). RESULTS: Increasing MAP in Group XC before crossclamping (81 + /-13 mmHg to 107 +/- 12 mmHg) caused an increase of Vs,mca (59 +/- 17 cm/s to 75 +/- 20 cm/s; p < 0.001). During crossclamping without a shunt, Vs,mca was not dependent on MAP, and was reduced (mean 47 +/- 24 cm/s) in relation to preclamp values. In Group S, Vs,mca was always dependent on MAP and the preclamp velocity was maintained (before shunt: 75 +/- 26 cm/sec; during shunt: 79 +/- 30 cm/sec). CONCLUSIONS: Although we found an impaired cerebral autoregulation, Vs,mca was independent of MAP during carotid crossclamping. Thus, TCD measurements have to be interpreted with caution during crossclamping, and the effect of induced hypertension has to be confirmed with more invasive measures of cerebral blood flow.     

超声监测在颈动脉内膜切除术围手术期的应用

目的探讨彩色多普勒超声（CDFI）与经颅多普勒超声（TCD）的联合应用,在颈动脉内膜切除术（CEA）中的临床价值。方法 CEA前采用CDFI和TCD评价186例患者颈动脉的狭窄程度及颅内侧支循环开放情况,将其结果与DSA对照。术中应用TCD对双侧大脑中动脉（MCA）在CEA不同阶段的血流动力学变化进行动态监测,指导转流管的使用。术后即刻行TCD和CDFI检查,评估手术前后术侧颈动脉的内径变化及颅内外血流动力学参数的变化。结果①186例患者CDFI检出狭窄程度与DSA完全一致的为178例,与DSA对照,CDFI判断颈动脉中、重度狭窄的符合率为95.7%。②术中CDFI和TCD监测的186例患者中,167例侧支循环建立良好,无需放置转流管,其余19例颈动脉压迫试验显示代偿不完全。③术后即刻复查CDFI、TCD,186例患者经CEA后狭窄均得到解除,管径明显增宽,狭窄处残余内径由（1.5±0.4）mm增至（5.9±0.7）mm,差异有统计学意义,P〈0.01;颈动脉狭窄处收缩期峰值流速（PSV）及患侧MCA的舒张期末血流速度（PSV）、血管搏动指数（PI）恢复正常。颈动脉狭窄处血流速度由术前（547±51）cm/s降至（89±28）cm/s（P〈0.01）;患侧MCA的PSV由术前（58±14）cm/s升至（80±5）cm/s（P〈0.01）;患侧MCA的PI由术前的0.56±0.11升至0.92±0.13（P〈0.01）,脑部血液供应得到明显改善。结论CDFI和TCD在CEA术前筛查、术中监测及术后评估中,提供了可靠的客观依据,在CEA围手术期有很重要的临床应用价值。     

Platelet Activation During Carotid Endarterectomy And the Antiplatelet effect of Dextran 40

Objective: To determine changes in platelet activation during carotid endarterectomy (CEA) and the antiplatelet effect of Dextran 40. Methods: Prospective study in 40 patients undergoing CEA. Platelet activity was measured by whole blood flow cytometry and platelet aggregometry during CEA. The expression of P-selectin and the PAC-1 antigen were used as markers of platelet activation and aggregation. Patients received aspirin (75-300 mg) preoperatively and 5,000 units unfractionated heparin during surgery. High intensity transient signals (HITS) in the ipsilateral middle cerebral artery were monitored using transcranial Doppler (TCD) perioperatively. Results: P-Selectin expression increased after carotid clamping (P < 0.01) and clamp release (P < 0.05). There was higher expression of PAC-1 after carotid clamping (p < 0.05). Spontaneous and ADP-induced platelet aggregation increased after carotid clamping (P< 0.01) and release (P < 0.01). TCD monitoring showed an increased HITS count from preoperative levels, after clamp release (P < 0.01) and during recovery (P < 0.01). After the operation, patients with more than 50 HITS per 30 min were started on an infusion of dextran 40 (n = 6). P-selectin expression decreased 24 h after dextran 40 (P < 0.01). Conclusion: Significant platelet activation and aggregation occurs during CEA despite the current use of antiplatelet treatment. Dextran 40 had an antiplatelet effect after CEA providing further evidence that it may contribute to reducing thromboembolic complications.     

经颅多普勒超声对颈动脉内膜切除术中选择性分流的评价

目的 采用经颅多普勒(transcranial Doppler,TCD)评价选择性分流在颈动脉内膜切除术(carotid endarterectomy,CEA)中的实施效果.方法 采用TCD对169例接受CEA治疗的颈动脉狭窄患者行术中双侧大脑中动脉(middle cerebral artery,MCA)脑血流连续监测.根据是否实施分流术,将患者分类为分流组(n=32)和未分流组(n=137).记录术前侧支循环开放途径,比较麻醉后、颈动脉夹闭前后、分流前后以及颈动脉开放后双侧MCA的收缩期峰值血流速度(peak systolic velocity,PSV)、平均血流速度(mean velocity,MV)、血管搏动指数(pulsatility index,PI)和MV变化率.结果 颈动脉夹闭前分流组与未分流组MV分别为(34.73±13.54)cm/s和(35.32±13.18)cm/s,无显著差异(P=0.825).颈动脉夹闭后分流组MV较未分流组显著降低(P=0.000),MCAMV下降率平均为69.34%±20.93%,较未分流组显著降低(P=0.000).分流后MCA MV显著提高,平均提高(35.68±16.69)cm/s(P=0.000).结论 TCD可客观评价分流前后的脑血流动力学改变.     

颈动脉内膜切除术治疗颈动脉重度狭窄中乌拉地尔降低血压对脑血流的影响

目的观察颈动脉内膜切除术(CEA)治疗颈动脉重度狭窄中,静脉给予乌拉地尔降低血压对患者脑血流的影响。方法回顾性纳入CEA中颈内动脉开放后,给予乌拉地尔降低血压控制脑血流的患者15例。记录颈内动脉夹闭后(T0)、开放即刻(T1)、开放后5 min(T2)、10 min(T3)的收缩压、舒张压、心率及超声检测患侧大脑中动脉收缩期峰值流速(PSV)、舒张期末流速(EDV)、平均流速(MV)、平均流速比值。结果 (1)血压T1时为(143±18/67±9)mm Hg降至T2时(126±19/60±10)mmHg,与T0和T1时比较,差异有统计学意义(P0.05),T3时降至(128±16/60±11)mm Hg(收缩压与T1时相比,P0.05)。心率无明显变化。(2)T2时患侧大脑中动脉PSV、EDV、MV及平均流速比值分别由T1时的(99±27)cm/s、(35±15)cm/s、(56±12)cm/s、(173±15)%降至(76±26)cm/s、(25±11)cm/s、(41±11)cm/s、(122±18)%,差异均有统计学意义(P均0.05),T3时分别降至(78±29)cm/s、(26±9)cm/s、(42±14)cm/s、(118±20)%,与T1时相比,差异均有统计学意义(P均0.05)。(3)1例患者用药后出现短暂性低血压,无心律失常发生。结论 CEA术中颈内动脉开放后,给予乌拉地尔降压可以安全有效降低大脑中动脉的血流速度,改善脑灌注。     

经颅多普勒超声经眼窗监测脑血流动力学在颈动脉内膜切除术中的应用价值

目的应用经颅多普勒超声（TCD）对颞窗穿透不良的颈动脉内膜切除术（CEA）患者经眼窗监测脑血流动力学的改变,探讨该方法的有效性及可靠性。方法经眼窗监测CEA手术患者8例。采用TCD评价术前侧支循环的开放情况,并经DSA证实。于术中进行脑血流监测,记录麻醉后、颈动脉夹闭前后、转流管放置及颈动脉开放前后,不同时间点患侧眼动脉（OA）和（或）颈内动脉虹吸部（CS）的收缩期峰值血流速度（PSV）、舒张期末血流速度（EDV）、平均血流速度（MV）、血管搏动指数（PI）等参数。结果①手术监测成功7例。8例患者中有4例因交通动脉代偿不良,使用转流管。术中采用双深度监测OA及CS者3例,单独监测CS者2例（1例未成功）,单独监测OA者3例。②夹闭颈动脉后与夹闭前比较,OA的PSV、MV、EDV及PI均显著下降,差异有统计学意义（P〈0.05）;颈动脉血流开放后,OA的PI明显升高（P〈0.05）;夹闭颈动脉后较夹闭前CS的PSV显著下降（P〈0.05）,但开放后血流与夹闭前各项参数比较,差异无统计学意义（P〉0.05）。③8例患者中,有1例术后1周发生脑梗死,7例预后良好。结论经眼窗监测CEA术中脑血流改变,可有效解决颞窗穿透不良的难题。采用双深度间断监测患侧OA和CS血流参数是较理想的方式。对前交通动脉和（或）后交通动脉代偿不完全患者,建议使用转流管,可预防术中脑缺血,降低术后卒中的发生。     

Evaluation of the effect of the sublingually administered nifedipine and captopril via transcranial doppler ultrasonography during hypertensive crisis

OBJECTIVE: This study was designed to show the effects of sublingually administered nifedipine and captopril on middle cerebral arterial blood flow during hypertensive crisis in the emergency department. METHODS AND RESULTS: Transcranial Doppler ultrasonography (TCD) was performed on the patients fulfilling the criteria (15 patients given captopril, 13 patients given nifedipine, mean (+/-SD) age 56 +/- 11 and 54 +/- 10 years, respectively). Then, patients were randomized into sublingually administered captopril or nifedipine groups and after the drug administration, TCD was repeated. Initial systolic and diastolic blood pressures were 200 +/- 21/125 +/- 21 mmHg in the captopril group and 199 +/- 17/ 123 +/- 20 mmHg in the nifedipine group. There was no significant difference between antihypertensive effects of the drugs after initiation of treatment. Before the treatment with captopril, middle cerebral artery (MCA) flow velocities (Vm) and pulsatility index (PI) were 76.74 +/- 6.38 cm/s and 1.18 +/- 0.09, respectively. The values after the treatment with captopril were 78.21 +/- 5.24cm/s (p < 0.05) and 0.92 +/- 0.08 (p < 0.001), respectively. Before the treatment with nifedipine, Vm and PIs were 64.73 +/- 5.11 cm/s and 1.14 +/- 0.18, respectively. After the treatment with nifedipine, Vm was 60.04 +/- 5.36 cm/s (p < 0.01) and PI was 1.21 +/- 0.09 (p < 0.01). CONCLUSION: After treatment with captopril, PIs were decreased to normal limits but in the group treated with nifedipine, PIs increased to more pathological values. These results showed that we should reconsider the use of nifedipine in the emergency departments as an antihypertensive agent in hypertensive attack treatment.     

Assessment of flow changes in the circle of Willis after stenting for severe internal carotid artery stenosis.

PURPOSE: To assess flow velocities in the cerebral arteries after carotid artery stenting (CAS) in patients with unilateral versus bilateral lesions and analyze velocities in patients with neurological complications after CAS. METHODS: Ninety-two patients (68 men; mean age 63.2 +/- 8.4 years, range 44-82) with internal carotid artery (ICA) stenoses were divided according to unilateral (group I, n = 72) or bilateral (group II, n = 20) disease. Fifty age- and gender-matched patients without lesions in the extra- or intracranial arteries served as a control group. Transcranial color-coded Doppler ultrasound was performed prior to and within 24 hours after CAS in the test groups; systolic velocities were assessed ipsilateral (i) and contralateral (c) to the CAS site in the middle cerebral artery (MCA) and anterior cerebral artery (ACA). RESULTS: Collateral flow via the anterior communicating artery (ACoA) was found in all group-II patients and 90% of group-I patients. After CAS, collateral flow through the ACoA ceased, and the velocity increased by 26% in the iMCA in group I compared to controls (p < 0.001). In group II, iMCA flow increased by 30% (p < 0.001) and flow via the ACoA (p < 0.001) increased, resulting in normalization of cMCA velocities (p = 0.928). In 89 (96.7%) subjects, CAS was uncomplicated. Hyperperfusion syndrome occurred in 2 (2.2%) patients, both with bilateral ICA stenoses; 1 (1.1%) transient ischemic attack was seen in a patient with unilateral disease. In the patients with hyperperfusion syndrome, the MCA velocities were 2.7- and 7.4-fold higher, respectively, versus before CAS and 2-fold higher than in controls. CONCLUSION: Uncomplicated CAS results in an iMCA velocity increase >25% compared to controls. MCA velocities in hyperperfusion syndrome were greatly increased versus before CAS and in controls.     

Hydroxyurea therapy lowers transcranial Doppler flow velocities in children with sickle cell anemia

Hydroxyurea has hematologic and clinical efficacy in sickle cell anemia (SCA), but its effects on transcranial Doppler (TCD) flow velocities remain undefined. Fifty-nine children initiating hydroxyurea therapy for clinical severity had pretreatment baseline TCD measurements; 37 with increased flow velocities (> or = 140 cm/s) were then enrolled in an institutional review board (IRB)-approved prospective phase 2 trial with TCD velocities measured at maximum tolerated dose (MTD) and one year later. At hydroxyurea MTD (mean +/- 1 SD = 27.9 +/- 2.7 mg/kg per day), significant decreases were observed in the right middle cerebral artery (MCA) (166 +/- 27 cm/s to 135 +/- 27 cm/s, P < .001) and left (MCA) (168 +/- 26 cm/s to 142 +/- 27 cm/s, P < .001) velocities. The magnitude of TCD velocity decline was significantly correlated with the maximal baseline TCD value. At hydroxyurea MTD, 14 of 15 children with conditional baseline TCD values improved, while 5 of 6 with abnormal TCD velocities whose families refused transfusions became less than 200 cm/s. TCD changes were sustained at follow-up. These prospective data indicate that hydroxyurea can significantly decrease elevated TCD flow velocities, often into the normal range. A multicenter trial is warranted to determine the efficacy of hydroxyurea for the management of increased TCD values, and ultimately for primary stroke prevention in children with SCA.     

应用经颅多普勒超声指导颈动脉内膜切除术中脑血流的调节

目的探讨颈动脉内膜切除术中，经颅多普勒超声（TCD）对血压与脑血流调节指导作用。方法回顾性分析颈动脉重度狭窄患者52例，在全身麻醉下行颈动脉内膜切除术，术中应用TCD监测大脑中动脉（MCA）血流参数，根据脑血流参数的变化调控血压，并决定术中是否应用临时转流管。应用临时转流管（转流组）16例，未用36例（非转流组）。结果①52例患者术后，完全恢复且无脑缺血发作50例，因过度灌注脑出血死亡2例。②颈动脉阻断前，转流组、非转流组平均动脉压（MAP）为（111±9）、（97±15）mmHg，两组比较差异有统计学意义，P〈0．01；MCA平均血流速度（MCA Vm）为（40±12）、（39±13）cm／s，差异无统计学意义。③阻断后，转流组、非转流组MAP为（118±8）、（106±9）mmHg，较阻断前差异均有统计学意义（P〈0．01）；MCA Vm为（14±8）、（33±16）cm／s，较阻断前均下降，平均血流速度变化率为（66±6）％、（15±5）％，P〈0．01。④转流组转流中，MAP（110±13）mmHg，接近阻断前水平；MCA Vm为（44±15）cm／s，MCA Vm较阻断前提高（10±2）％。⑤开放后两组MAP为（90±12）、（93±11）mmHg；MCA Vm为（55±19）、（54±23），较阻断前提高，平均血流速度变化率为（36±3）％、（37±4）％。差异均有统计学意义，P〈0．05。⑤术中转流组、非转流组呼气末二氧化碳分压为（31．0±2．5）、（31．8±2．2）mmHg，差异无统计学意义。结论颈动脉内膜切除术中应用TCD监测，可评价脑血流灌注情况，指导血压的调控及术中转流管的选择。     

Effects of intraaortic balloon pumping on coronary hemodynamics after coronary angioplasty in patients with acute myocardial infarction.

It has been reported that intraaortic balloon pumping can prevent reocclusion after coronary angioplasty for acute myocardial infarction. The speculated mechanism has been the production of markedly enhanced diastolic coronary perfusion pressure; however, most studies have reported that intraaortic balloon pumping has little effect on coronary blood flow. To assess the effectiveness of this procedure, we studied 12 patients with acute anterior myocardial infarction who were undergoing coronary angioplasty and intraaortic balloon pumping. After successful angioplasty, coronary blood flow velocity was measured with a coronary Doppler catheter before and during intraaortic balloon pumping. Although mean coronary blood flow velocity was unchanged, intraaortic balloon pumping increased peak coronary blood flow velocity from 34.6 +/- 5.0 cm/sec (mean +/- SEM) to 46.7 +/- 5.8 cm/sec (p < 0.005). Such an increase in peak coronary blood flow velocity seemed to be a mechanism by which intraaortic balloon pumping could prevent reocclusion after coronary angioplasty for acute myocardial infarction.     

Correlation of abnormal intracranial vessel velocity, measured by transcranial Doppler ultrasonography, with abnormal conjunctival vessel velocity, measured by computer-assisted intravital microscopy, in sickle cell disease

The Stroke Prevention Trial has confirmed that utilization of transcranial Doppler ultrasonography (TCD), which examines blood flow in large intracranial vessels, can identify children with sickle cell disease (SCD) who are at high risk of developing a premature stroke. It is not known to what extent the vasculopathy in SCD involves small vessels and whether the abnormalities, if present, correlate with large-vessel vasculopathy. Eighteen children with SCD were examined with TCD to determine middle cerebral artery (MCA) velocity and computer-assisted intravital microscopy (CAIM) to determine bulbar conjunctival vessel velocity during the same visit for vasculopathy correlation. High MCA velocity (> or = 200 cm/sec) was found by TCD in 4 patients who also showed abnormal conjunctival velocity (< 0.2 mm/sec or intermittent trickle flow) by CAIM. Three patients had conditional (> or = 170 cm/sec and < 200 cm/sec) MCA velocity: 2 showed abnormal (trickle) and 1 showed normal conjunctival velocity (1.9 mm/sec). One patient with unmeasurable MCA velocity had abnormal (trickle) conjunctival velocity. Of the remaining 10 patients who had normal MCA velocity, 2 showed abnormal (0.05 mm/sec and 0.1 mm/sec) and 8 showed normal conjunctival velocities (1.1-2.4 mm/sec). The MCA velocities correlated significantly with bulbar conjunctival flow velocities (P < or =.008, Fisher exact test). A correlation exists between MCA (large-vessel) and conjunctival (small-vessel) flow velocities. CAIM is a noninvasive quantitative technique that might contribute to the identification of SCD patients at high risk of stroke. Small-vessel vasculopathy might be an important pathological indicator and should be further explored in a large-scale study. (Blood. 2001;97:3401-3404)     

Prognostic significance of Doppler-derived left ventricular diastolic filling variables in dilated cardiomyopathy.

To determine the prognostic significance of pulsed wave Doppler-derived left ventricular diastolic filling velocity profiles and the relationship between Doppler variables and clinical functional status, the follow-up outcomes of 62 consecutive patients with dilated cardiomyopathy and symptoms of left ventricular dysfunction were analyzed. All patients had echocardiographic left ventricular end-diastolic dimension > or = 6.0 cm, fractional shortening < 25%, increased E pointseptal separation, and diffuse hypokinesia or akinesia. During a mean follow-up period of 30.5 +/- 13.9 months, 27 patients experienced cardiac events: 23 died of either progressive pump failure or an episode of sudden death and four required cardiac transplantation because of refractory heart failure. Peak early filling velocity (78 +/- 23 cm/sec vs 65 +/- 25 cm/sec; p < 0.03) was higher and late atrial filing velocity (34 +/- 13 cm/sec vs 55 +/- 19 cm/sec; p < 0.001) was lower in patients with cardiac events than in cardiac event-free survivors. The ratio of early to late transmitral filling velocities was higher (2.6 +/- 1.2 vs 1.5 +/- 1.3; p < 0.001), and the deceleration time of early diastole was shorter (133 +/- 48 msec vs 175 +/- 71 msec; p < 0.001) in patients with cardiac events. The cardiac event rate was significantly higher in patients with an early to late filling velocity ratio greater than 2 (77% vs 19%; p < 0.001) or a deceleration time less than 150 msec (58% vs 23%; p < 0.05) than in those without. Stepwise multivariate regression analysis revealed that the pattern of transmitral early to late filling velocity ratio was the only significant independent Doppler echocardiographic predictor of outcome for these patients. Repeat Doppler echocardiographic examinations, which were performed in 31 survivors after intensive treatment (mean, 38.6 +/- 6.5 months), showed that early filling velocity was decreased (55 +/- 20 cm/sec vs 75 +/- 25 cm/sec; p < 0.02), late atrial filling velocity was increased (74 +/- 27 cm/sec vs 57 +/- 21 cm/sec; p < 0.01), early to late filling velocity ratio was reduced (0.8 +/- 0.3 vs 1.7 +/- 1.3; p < 0.001), and deceleration time was prolonged (227 +/- 60 msec vs 167 +/- 82 msec; p < 0.01) in 18 patients with clinical functional improvement, whereas these measurements were unaltered in the remaining 13 patients whose functional status was unchanged or had deteriorated.(ABSTRACT TRUNCATED AT 400 WORDS)     

Cerebrovascular response time to a breath-holding challenge

BACKGROUND: To evaluate the timecourse of cerebrovascular reserve response to breath-holding. PATIENTS AND METHODS: Using simultaneous bilateral transcranial Doppler (TCD) recordings from the MCA during a breath-holding challenge, we measured the time interval between baseline and peak blood flow velocity values in 25 patients with critical unilateral internal carotid artery (ICA) stenosis (> 85% lumen diameter reduction), in 9 patients with a non-critical (70-85%) ICA-stenosis and in 27 normal controls. RESULTS: Normal controls and patients with non-critical stenosis reached peak MCA velocities on both sides almost simultaneously. For the patients with critical stenosis the peak response time ipsilateral to the stenosis was delayed 2.40 +/- 3.43 sec compared to the opposite side. This delay resolved after carotid endarterectomy. CONCLUSIONS: In response to a breath-holding challenge unilateral critical ICA stenosis is associated with a significant ipsilateral prolongation of the rise time from baseline to peak MCA velocity.     

Transcranial Doppler monitoring during percutaneous transluminal aortic valvuloplasty

Cerebral blood flow was studied in 12 elderly patients with severe calcific aortic stenosis by means of transcranial Doppler sonography (TCD) during percutaneous transluminal aortic valvuloplasty (PTAV). In 8 of these 12 patients duplex sonography revealed a stenosis of the internal carotid artery (ICA) exceeding 50%. Frequency spectra of 10 patients showed a satisfactory quality and were analyzed. In 7 subjects balloon inflation was well tolerated and systolic blood pressure did not drop below 75 mmHg. In these patients, whether they had a stenosis of the ICA or not, blood flow velocity in the middle cerebral artery (MCA) did not decrease to a critical level. The authors defined "critical" as a reduction of mean blood flow velocity in the MCA exceeding 50% or a decrease below 35 cm/sec. Three patients showed a rapid decrease of systolic aortic pressure below 75 mmHg. In these subjects mean blood flow velocity in the MCA dropped to levels below 35 cm/sec. Deflation and retraction of the balloon resulted in a rapid increase of systemic blood pressure and flow velocity in the MCA. This report demonstrates TCD to be a useful monitoring method of determining residual perfusion in patients with aortic stenosis during PTAV.     

Doppler and echocardiographic assessments of effects of disopyramide on non-obstructive hypertrophic cardiomyopathy

We assessed the effects and therapeutic implications of disopyramide on left ventricular systolic and diastolic functions in 19 patients with non-obstructive hypertrophic cardiomyopathy by Doppler echocardiography. All patients were in sinus rhythm. Parameters measured were fractional shortening (FS (%)), mean velocity of circumferential fiber shortening (mean Vcf (circ/sec)), ejection fraction (EF (%)), peak left ventricular outflow velocity (peak-LVOT (cm/sec)), peak rapid filling inflow velocity (peak-R (cm/sec)), peak late filling inflow velocity (peak-A (cm/sec)) and peak-A/peak-R ratio (A/R ratio). These values were compared before and after infusion of disopyramide (2 mg/kg). There was no significant difference in heart rate, systolic and diastolic blood pressures before and after infusion of disopyramide. Following the intravenous drip infusion of disopyramide, FS decreased from 38.1 +/- 5.4 to 33.2 +/- 4.9 (p less than 0.05) and the mean Vcf decreased from 1.285 +/- 0.181 to 1.141 +/- 0.188 (NS). EF and peak-LVOT also decreased from 67.7 +/- 6.3 to 61.9 +/- 7.0 (p less than 0.05), and from 107.6 +/- 29.5 to 92.4 +/- 25.2 (p less than 0.01), respectively. The infusion of disopyramide increased the peak-R from 47.3 +/- 18.2 to 55.5 +/- 19.2 (p less than 0.05), and decreased peak-A from 52.0 +/- 13.6 to 40.2 +/- 12.6 (p less than 0.01), resulting in a decrease of A/R ratio from 1.277 +/- 0.537 to 0.818 +/- 0.475 (p less than 0.01). These results suggest that disopyramide improved left ventricular diastolic function, although systolic function decreased slightly. In conclusion, disopyramide can be also used beneficially in non-obstructive hypertrophic cardiomyopathy without arrhythmias.     

Invos Cerebral Oximeter compared with the transcranial Doppler for monitoring adequacy of cerebral perfusion in patients undergoing carotid endarterectomy.

AIM: The aim of this prospective study was to assess the correlation between signals obtained during carotid endarterectomy (CEA) under local (LA) or general anesthesia from the Somanetics Invos cerebral oximeter (CO) and transcranial Doppler (TCD). METHODS: Forty patients were enrolled in the study. The percentages fall in TCD mean flow velocity (FVm) and CO regional oxygen saturation (rSO2) on the ipsilateral side following clamping were recorded and the correlation coefficient and Spearman's coefficient of rank correlation were calculated. RESULTS: Fourteen patients were not included in the statistical analysis because either no TCD window or reliable TCD signal was obtained. The remaining 26 patients had a fall in either FVm, rSO2 or both during carotid clamping. There was a highly statistically significant correlation between the percentage fall in FVm and rSO2 with a correlation coefficient of 0.73, P<0.0001, with a 95% confidence interval (CI) for r=0.48 to 0.87; Spearman's coefficient of rank correlation (rho) =0.67, P=0.0008, with a 95% CI for rho=0.384 to 0.84. A significant decline in both TCD and rSO2 was noted in 3 patients under LA out of which 2 required shunts for alteration in conscious level. In 2 LA patients there was a significant decline in TCD but not in rSO2 and the endarterectomy was completed without a shunt. CONCLUSIONS: Regional oxygen saturation correlates well with FVm during carotid clamping. However, the inability to obtain reliable TCD FVm readings in 35% of patients is a serious disadvantage for this monitor. It appears that CO is a satisfactory and possibly superior device for monitoring adequacy of cerebral perfusion and oxygenation during CEA in comparison with the TCD.     

Investigation on cerebral hemodynamics in patients with carotid disease receiving carotid endarterectomy

100 patients (pts) receiving CEA (carotid endarterectomy) were evaluated in this study. In some of them postoperative complications were observed, characterized by TIA (transient ischemic attack) and, mostly, by cerebral hyperperfusion. In only two of the pts investigated CEA needed the implantation of a shunt, due to the emergence of intolerance signs at carotid Clamping (C) evaluated by TCD (transcranial Doppler); the preoperative cerebral angiography in the two subjects in question did not show malformations of the circle of Willis. The hyperperfusive phenomenon and the absence of intracranial compensation flows during CEA seemed to be ascribed to a more or less severe impairment of cerebral reserve. Such impairment of the autoregulatory capacity seems to be crucial to the pathogenesis of hemodynamic stroke. Thus the indication to CEA, in pts with severe carotid disease, should take into account also the cerebral reserve (CR) impairment to prevent both thromboembolic and hemodynamic stroke. The predictive and diagnostic role of TCD turns out to be crucial in assessing and selecting pts candidate to CEA.     

Doppler echocardiographic evaluation of left ventricular diastolic function in patients with systemic lupus erythematosus

Subclinical myocardial involvement frequently occurs in patients with systemic lupus erythematosus (SLE). In this study, left ventricular diastolic function was assessed in 58 patients (54 female and 4 male; mean age 32 +/- 11 years) and in 40 sex-matched and age-matched healthy control subjects (37 female and 3 male; mean age 33 +/- 9 years) by means of pulsed Doppler echocardiography. All subjects had no clinical evidence of overt myocardial disease or abnormal left ventricular systolic function. Compared with the control group, patients with SLE had significantly prolonged isovolumic relaxation time (62 +/- 12 vs 80 +/- 14 msec; p less than 0.01), reduced peak early diastolic flow velocity (peak E) (82 +/- 18 vs 76 +/- 16 cm/sec; p less than 0.05), increased peak late diastolic flow velocity (peak A) (45 +/- 7 vs 53 +/- 8 cm/sec; p less than 0.01), reduced E/A ratio (1.81 +/- 0.32 vs 1.46 +/- 0.29; p less than 0.001), and lower deceleration rate of early diastolic flow velocity (EF slope) (489 +/- 151 vs 361 +/- 185 cm/sec2; p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)