应用多普勒超声心动图研究心律失常血流动力学变化

应用脉冲波多普勒超声心动图（ＰＷＤＥ）对４０名室性早搏（ＶＰＢ），１３名房性早搏（ＡＰＢ）及５名单纯性心房纤颤（Ａｆ）患者心律失常发生的血流动力学变化进行了研究。结果表明，早搏对心脏血流动力学的影响与其联律间期（ＣＩ）及左室舒张功能有关。还就心率、年龄、早搏的类型等对早搏瞬间血流动力学的影响进行了分析。     

Echocardiography-guided biventricular pacemaker optimization: role of echo Doppler in hemodynamic assessment and improvement

In spite of improvements in heart failure management and increasing utilization of cardiac resynchronization therapy (CRT), approximately 30–40% of CRT patients remain nonresponders and 50% or more are echocardiographic nonresponders (defined as less than 15% reduction in left ventricular end systolic volume post-CRT). Optimization guided by echocardiography has been studied as one of the methods to improve the nonresponder rate to CRT. Echo-guided biventricular (Biv) pacemaker optimization has been associated with improvement in acute cardiac hemodynamics and improvement in functional class. In this review, the authors discuss various methods to optimize Biv pacemaker by echocardiography, recent advances in pacemaker optimization and the limitations of echocardiography. The authors also demonstrate complex hemodynamic derangements in heart failure via multiple case examples highlighting the role of comprehensive echo Doppler in elucidating cardiac hemodynamics encountered in CRT nonresponders, as well as tailoring of Biv pacemaker optimization to the underlying physiologic derangement.     

The Value of Two-Dimensional Echocardiography and Pulsed Doppler Technique in Facilitating Percutaneous Catheterization of the Suhclavian Vein

We have found combined two-dimensional echocardiographic imaging and range-galed pulsed Doppler flow mapping to he very useful and accurate in identifying the location and course of the subclavian vein. It can he efficiency utilized to minimize the incidence of iatrogenic complications during percutaneous central venous catheterization. This is particularly relevant in patients who are predisposed to a high risk of complications from the procedure.     

Implantation of permanent dual chamber pacemaker in a pregnant woman by transesophageal echocardiographic guidance

A 37-year-old woman complained of fatigue and dizziness because of intermittent sinus arrest and asystole up to 5.2 seconds. She was 3 months into her pregnancy and a dual chamber permanent pacemaker was implanted by transesophageal echocardiographic guidance.     

Pulsed tissue Doppler imaging for the detection of myocardial ischaemia, a comparison with myocardial perfusion SPECT

In order to compare the diagnostic ability of pulsed tissue Doppler and myocardial perfusion Single Photon Emission Computed Tomography (SPECT) in patients with a history of unstable coronary artery disease, CAD, 26 patients, 22 men and four women, age 47-76 years, were investigated in a prospective study, 5-10 day after an episode of unstable angina. Tissue Doppler and two-dimensional echocardiography were performed during dobutamine stress testing and myocardial scintigraphy after bicycle exercise and at rest. Patients with a normal SPECT had higher peak systolic velocity during dobutamine infusion, 18.9 +/- 4.1 cm s(-1), than patients with ischaemia, 12.2 +/- 3.8 cm s(-1) (P<0.001) or scar, 8.8 +/- 3.0 cm s(-1) (P<0.01). In a territorial analysis the difference in peak systolic velocity between areas with a normal and abnormal SPECT was less apparent. Failure to achieve >/=13 cm s(-1) in mean-peak systolic velocity was the most accurate criterion for detection of significant CAD on SPECT. We conclude that pulsed tissue Doppler can be used for objective quantification of left ventricular wall motion during dobutamine stress testing and for identification of patients with CAD on SPECT but not for identification of regional ischaemia.     

Assessment of regional wall motion by strain Doppler during biventricular pacing in patients with conventional indications for a pacemaker

Biventricular pacing therapy is effective in patients with severe congestive heart failure. Strain Doppler imaging (SDI) is a new tool for measuring regional myocardial deformation. We evaluated regional wall motion by strain Doppler imaging in 13 patients who had conventional indications for a pacemaker (74 +/- 6 years old) and in six with NYHA Class III or IV heart failure with a biventricular pacemaker (HF-RV: during right ventricular pacing, HF-BV: during biventricular pacing). The other seven patients had normal LV function (N-RV). Wall motion was assessed by strain of the myocardium, and the interval between the Q wave of the surface ECG and the peak strain (QPSI) was measured in three septal and three lateral segments. Interventricular contraction delay was determined as the interval between the onset of the left and right ventricular outflow waves. Intraventricular contraction delay was determined as the time difference between minimum and maximum QPSI. Strain of HF-RV was significantly greater than that of N-RV (-9.6%+/- 2.5% vs -14.4%+/- 2.3%, P < 0.0001). Intraventricular contraction delay of HF-RV was significantly greater than that of N-RV (273 +/- 12 vs 151 +/- 69 ms, P = 0.0004). Strain of HF-RV was not significantly greater than that of HF-BV (-9.6% +/- 2.5% vs -10.6% +/- 2.9%). Interventricular contraction delay of HF-RV was greater than that of HF-BV (37.2 +/- 44.7 vs 16.2 +/- 47.4 ms, P < 0.0001). Intraventricular contraction delay of HF-RV was significantly greater than that of HF-BV (322 +/- 101 vs 209 +/- 88 ms, P = 0.0006). In conclusion, biventricular pacing improves both interventricular contraction delay and intraventricular contraction delay in patients with conventional indications for a pacemaker with severe congestive heart failure, and SDI is useful to predict the efficacy of biventricular pacing.     

Percutaneous permanent pacemaker implantation via the azygous vein in a patient with superior vena cava occlusion

Occlusion of the superior vena cava (SVCO) makes implantation of permanent pacemakers challenging and difficult. We describe an extended application of a Medtronic Attain (Medtronic Inc., Minneapolis, MN, USA) guide catheter (a tool designed for delivery of left ventricular pacing leads into the coronary sinus) for delivery of a right ventricular pacing lead via the azygous vein in a 72-year-old woman with SVCO secondary to long-term central venous hemodialysis catheters. This approach allowed the use of an endocardial pacing lead, implantation under local anesthesia, and conventional positioning of the pacemaker generator in the pectoral region in a patient with SVCO.     

Successful pacemaker lead implantation via the subclavian vein despite of high degree stenosis of the vein

This case reports on an 81-year-old man with implanted dual-chamber pacemaker for binodal disease who required ventricular lead revision due to loss of ventricular capture. Successful placement of a new lead via the subclavian vein despite of high degree stenosis of the medial part of the vein is described using a very thin bipolar ventricular pacing lead. Currently available pacing electrodes for this purpose are reviewed.     

心脏起搏器植入术围术期预防性抗菌药物使用分析及围术期护理体会

目的分析本院心脏起搏器植入术围术期预防性抗菌药物使用情况以及在使用过程中存在的问题。方法对125例心脏起搏器植入术围术期预防性抗菌药物使用情况进行回顾性调查分析。结果使用的抗菌药物涉及头孢菌素类、青霉素类、喹诺酮类以及林可霉素类4大类,其中抗菌使用率最高的是头孢呋辛,占55.2%,其次是头孢美唑,占21.6%;抗菌药物用量最多的是头孢呋辛,其次为头孢美唑钠;平均用药时间(3.2±1.3)d;术后有1例感染,给予头孢呋辛抗感染,并及时将切口处消毒换药处理,术后第9天拆线出院。结论本院心脏起搏器植入术围术期预防性抗菌药物选择给药方面较为合理,但仍存在一定比例的不合理用药,并且还存在用药量过大及用药时间过长的问题,因此还需进一步加强管理,坚决将不合理用药使用率最大化降低。     

Treatment of sick sinus syndrome in a patient with cardiac lymphoma via chemotherapy without pacemaker implantation: A case report

Successful treatment of the acute phase of bradycardia in patients with cardiac lymphoma via medical therapy alone has not been reported. This case report describes the successful treatment of sick sinus syndrome in an 84‐year‐old man with cardiac lymphoma via chemotherapy without pacemaker implantation.     

Method of atrioventricular programming in atrial flutter in patients with biventricular pacemaker

BACKGROUND: Atrial flutter is a common cause of exacerbation of congestive heart failure (CHF). Typically, during atrial tachycardia, pacemakers, both dual and biventricular, are programmed to ignore atrial tracking. Virtually all current pacemakers and defibrillators use a programmable mode switch algorithm to switch between atrial tracking modes (DDD, DDDR) to nontracking modes (DDIR, DDI, VVI) during episodes of atrial tachycardia. METHODS: In this report, we describe a novel method of atrioventricular (AV) pacemaker programming in four patients with atrial flutter and CHF who remained symptomatic postbiventricular pacemaker implantation. All patients had chronic atrial flutter upon interrogation; adjustment of AV delay and postventricular atrial refractory period (PVARP) was performed to enable sensing of every second to fourth atrial flutter beat by the atrial lead. Mode switch was turned "OFF" in all points, and lower and upper rate limits were set to 50 and 100 bpm. Once sequential early and late diastolic filling was seen on mitral inflow pulsed-wave (PW) Doppler, further adjustment of AV delay and PVARP was performed until the highest and broadest atrial velocity occurred on mitral inflow PW Doppler. RESULTS: All patients developed improvement in aortic ejection duration and peak ejection velocity during AV optimization. Repeat ECG in these patients at 8 months, 7 days, 2 days, and 2 months postoptimization showed no change in P and QRS relationship. All patients developed improvement in CHF symptoms postbiv pacemaker optimization. CONCLUSION: In symptomatic patients with CHF and stable atrial flutter who have a biventricular pacemaker, atrial mechanical contribution to cardiac output can be achieved by adjusting PVARP and AV delay during echo-guided pacemaker programming.     

24 h动态心电图检查在起搏器植入心律失常诊断中的应用价值

目的探究24 h动态心电图检查在起搏器植入心律失常诊断中的应用价值。方法回顾性分析2013年8月至2019年7月中国人民解放军联勤保障部队第九〇一医院收治的78例起搏器植入术治疗患者,分别采用12导联心电图(列为A组)、24 h动态心电图(列为B组)进行监测。比较2组方案的起搏器功能异常率、心律失常检出率、心率变异性(HRV)时域指标变化及术后心肌缺血检出情况。结果B组起搏器功能异常率、心律失常检出率分别为47.4%、80.8%,均分别高于A组的7.7%、80.8%,差异有统计学意义(P均<0.001)。B组24 h内正常RR间期标准差(SDNN)、全程每5 min时段RR间期均值标准差(SDANN)及24 h内相邻正常RR间期之差均方根值(RMSDD)分别为(137.25±15.98)、(132.92±15.43)、(39.25±11.36)ms,分别高于A组的(91.39±14.36)、(87.15±17.61)、(21.65±9.25)ms,差异有统计学意义(P<0.001)。B组术后心肌缺血ST-T改变检出率为26.9%,高于A组的5.1%,差异有统计学意义(P<0.001)。结论起搏器植入术后应用24 h动态心电图监测可进一步提高起搏器功能异常、心律失常检出率,其HRV敏感性较高,且有助于提高术后心肌缺血检出率。     

The value of two-dimensional echocardiography and pulsed Doppler technique in facilitating percutaneous catheterization of the subclavian vein

We have found combined two-dimensional echocardiographic imaging and range-gated pulsed Doppler flow mapping to be very useful and accurate in identifying the location and course of the subclavian vein. It can be efficiently utilized to minimize the incidence of iatrogenic complications during percutaneous central venous catheterization. This is particularly relevant in patients who are predisposed to a high risk of complications from the procedure.     

Pulsed Doppler echocardiography in the assessment of tricuspid regurgitation

Pulsed Doppler echocardiography is a noninvasive method with high sensitivity and specificity for the assessment of tricuspid regurgitation. In patients with tricuspid regurgitation, pansystolic unusual Doppler signals are detected in the right atrial cavity, which are interpreted as tricuspid regurgitant flow signals. They distributed in a spindle-shaped area from the tricuspid orifice toward the right atrial posterior wall in parallel with the interatrial septum. The orientation of the range where the regurgitant Doppler signals are detected in the right atrial cavity shows the direction of the regurgitant jet. However, such a result is determined mainly in patients with functional tricuspid regurgitation. In regard to patients with organic tricuspid lesion, different considerations may be necessary. Semiquantitative grading of the severity of regurgitation is possible, based on the distance covered by the regurgitant signals from the tricuspid orifice. Tricuspid regurgitation is demonstrated also by contrast echocardiography. The severity is graded based on the distance reached by regurgitant curvilinear contrast echoes from the tricuspid valve in the M-mode echocardiography. If the ultrasound beam is adequately directed through the tricuspid orifice, the grade estimated by the contrast echoes are well correlated with that by the Doppler. However, if the M-mode is performed without the guide by the two-dimensional image, it may miss the most adequate beam direction for the observation, resulting in underestimating severity. The influences of tricuspid regurgitation are generally seen in the flow pattern of the major veins. However, they are more sharply reflected by the flow condition in the right atrial cavity than by the flows patterns in the major veins.     

Parametric detection and measurement of perfusion defects in attenuated contrast echocardiographic images.

OBJECTIVE: Attenuation of radio frequency (RF) signals limits the use of contrast echocardiography. The harmonic-to-fundamental ratio (HFR) of the RF signals compensates for attenuation. We tested whether HFR analysis measures the left ventricular nonperfused area under simulated experimental attenuation. METHODS: Radio frequency image data from short axis systolic projections were obtained from 11 open-chest dogs with left anterior descending or left circumflex coronary artery occlusion followed by left atrial bolus injection of a perflutren microbubble contrast agent. Clinical attenuation was simulated by calibrated silicone pads interposed between the epicardial surface and the transducer to induce mild (7-dB) and severe (14-dB) reduction of the backscattered RF signals. Harmonic-to-fundamental ratio values were calculated for each image pixel for 0-, 7-, and 14-dB attenuation conditions and reproducibly showed a "perfused area" and a "nonperfused area." A reference nonperfused area was obtained by manual delineation in high-quality contrast scans. RESULTS: Correlations of the HFR-detected and manually outlined perfusion defect areas were R = 0.92 for 0 dB, R = 0.94 for 7 dB, and R = 0.90 for 14 dB; the mean difference was less than 0.36 cm(2) (negligible) in all 3 attenuation settings. Conclusions. Attenuation compensation by our HFR method allows precise measurement of myocardial perfusion defect areas in contrast scans with simulated high level of attenuation.     

Two-dimensional echocardiographic recognition of a pacing catheter perforation of the interventricular septum

A case of a pacing catheter perforation of the interventricular septum is presented here. The entire catheter length was visualized by two-dimensional real-time echocardiography utilizing the subcostal approach; the catheter was seen entering the left ventricle through the high interventricular septum.     

Doppler echocardiographic analysis of cardiac flow during the Mueller manoeuver

The inspiration against a closed airway, the Mueller manoeuver, leads to a negative intrathoracic pressure. It is controversially discussed whether this is causing an augmentation of right heart murmurs. There is only limited knowledge on the temporal relationship of the negative intrathoracic pressure with right and left ventricular filling and stroke volume. To investigate this relationship, the flow through the mitral, aortic, tricuspid and pulmonary valves was studied continuously by Doppler echocardiography during a standardized Mueller manoeuver in 15 healthy subjects (age 45 +/- 10 years). Five heart beats after the initiation of the manoeuver, flow through the mitral and aortic valve decreased 12.2 +/- 7.2% (P less than 0.001) and 10.1 +/- 6.6% (P less than 0.001), respectively. A transient increase of 15.1 +/- 9.2% (P less than 0.001) in tricuspid flow was followed by a 14.3 +/- 9.8% (P less than 0.005) increase of flow through the pulmonary artery. Ten heart beats after the initiation of the Mueller manoeuver, flow through the pulmonary artery again reached baseline, while tricuspid flow remained below baseline values. In contrast to previous studies, our results indicate that the Mueller manoeuver causes a small and transient increase in right ventricular stroke volume which is unlikely to cause a marked augmentation in right heart murmurs.     

Implantation of a dual-chamber pacemaker in a patient with dextrocardia and sick sinus syndrome: a case report

Dextrocardia is a congenital abnormal position of the heart in which the main part of the heart is in the right chest, and the long axis of the heart points to the lower right. Cases of a combination of dextrocardia and sick sinus syndrome are rare. A 65-year-old female patient was admitted to hospital with palpitations and dizziness for 1 week. Mirror-image dextrocardia and sick sinus syndrome were diagnosed by an electrocardiogram, echocardiography, Holter monitoring, and X-rays. Finally, we successfully implanted a dual-chamber pacemaker into the patient. The patient had an uneventful recovery and was discharged when her symptoms had greatly improved 1 week later. When dextrocardia is present, using active fixation leads in the atrial and ventricular leads is easier for finding the pacing position with optimal sensing and pacing thresholds, and they reduce the incidence of falling off.