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P Hanrath

Publications and source records attributed to P Hanrath.

At least 145 records · Page 8Linked to original sources
PubMed1998

Fragmentation of massive pulmonary embolism using a pigtail rotation catheter.

STUDY OBJECTIVES: The purpose of this study was the evaluation of the efficacy and safety of mechanical fragmentation of acute massive pulmonary emboli with a rotatable pigtail catheter. MATERIAL AND METHODS: Ten patients (4 female, 6 male, age 53.8+/-9.5 years) with acute massive pulmonary embolism with hemodynamic impairment were included in the study. The fragmentation catheter device (William Cook Europe A/S; Bjaerverskov, Denmark) consisted of a 5F catheter embedded in a flexible 5.5F sheath. Pulmonary emboli were fragmented by mechanical action of the recoiled rotating pigtail, while the guide wire was exiting an oval side hole proximal to the pigtail tip. In eight cases, an additional thrombolysis was performed. RESULTS: Fragmentation was successful in 7 of 10 patients. Average percentage of recanalization by fragmentation was 29.2+/-14.0%, and 36.0+/-10.0% exclusively of the seven successful cases. Average shock index decreased significantly prefragmentation to postfragmentation from 1.52 to 1.22 (p = 0.03) and to 0.81 48 h later (p < 0.001). Decrease of the average mean arterial pulmonary pressure prefragmentation to postfragmentation was insignificant (from 33 to 31 mm Hg, p = 0.14); further decrease within the 48 h follow-up was highly significant (from 31 to 21 mm Hg, p < 0.001) due to a synergy of fragmentation and thrombolysis (average dose 63+/-25 mg plasminogen activator). There were no procedure-related complications. Overall mortality rate was 20%. CONCLUSION: Fragmentation of massive pulmonary emboli with the pigtail rotation catheter achieved rapid partial recanalization in most cases, with ease of instrumentation, and without complications. Hemodynamic stabilization was completed in synergy with thrombolysis.

Acute Disease↗
PubMed1998

Quantitative assessment of transient regional ischemia during rotational atherectomy.

UNLABELLED: Sustained myocardial ischemia with angina pectoris, electrocardiographic changes and subsequent non-Q-wave infarctions has been reported during percutaneous transluminal rotational atherectomy of complex coronary lesions. The purpose of this study was to evaluate the effect of rotational atherectomy on regional myocardial perfusion as assessed by serial 99mTc-sestamibi SPECT imaging with semiquantitative tracer uptake analysis. METHODS: Twenty-nine consecutive patients with anginal symptoms, complex coronary lesions (all Type B and Type C) and preserved left ventricular function were studied using resting 99mTc-sestamibi SPECT before rotational atherectomy, during and 2 days after the procedure. For semiquantitative computerized analysis, the left ventricular myocardium was divided into 24 regions, and regional perfusion was expressed as percentage of maximal sestamibi uptake. RESULTS: Visual analysis of scintigraphic images revealed transient perfusion defects corresponding to the revascularized vessel in 26 of 29 patients, whereas three patients had no transient hypoperfusion. During rotational atherectomy, perfusion decreased significantly (>2 s.d. below normal mean) in 3.1 +/- 2.4 regions (range 1-10). Perfusion in the territory of the revascularized vessel was 75% +/- 11% at baseline, decreased to 67% +/- 12% during rotational atherectomy (p < 0.001) and normalized again after rotational atherectomy to 78% +/- 8% (p < 0.001). Similarly, perfusion in the region with the maximal reduction decreased from 74% +/- 15% at baseline to 55% +/- 14% (p < 0.001) during the procedure and returned to 74% +/- 16% (p < 0.001) following the intervention. In calcified stenoses, the extent of perfusion defects was larger as compared to noncalcified (4.2 +/- 2.5 versus 2.3 +/- 2.0 regions/patient, p < 0.05). CONCLUSION: During rotational atherectomy, myocardial hypoperfusion occurs. The transient nature of this perfusion defect can be demonstrated and quantified by serial 99mTc SPECT. This model may prove useful to assess the effects of pharmacological approaches to reducing myocardial hypoperfusion during coronary rotational atherectomy.

Atherectomy, Coronary↗
PubMed1998

[Chronic myocardial ischemia: indications and limits of dobutamine stress echocardiography].

Dobutamin echocardiography has turned out to be a reliable tool for the detection of myocardial viability in the setting of acute and chronic myocardial ischemia. Moreover, recent publications have highlighted the prognostic implications of the method in patients with acute myocardial infarction and in patients with chronic myocardial ischemia and reduced left ventricular function. In comparison to szintigraphy dobutamine echocardiography has shown higher specificity and accuracy for the prediction of functional recovery of chronic dysfunctional segments after revascularization procedures. Reasons for the discrepancy include the different methodological approaches of the two techniques for the detection of viability, i.e., functional recovery versus metabolic integrity and perfusion. Furthermore, existing evidence supports the concept that functional recovery is dependend on a threshold level of viable contracting myocardium, whereas metabolic integrity and perfusion will be even detected at a level below that necessary for functional recovery. Limitations of the method include poor transthoracic image quality in a variable subset of patients and the subjective nature of the analysis of wall motion abnormalities by the investigator.

Cardiotonic Agents↗
PubMed1997

Recanalization of total coronary occlusions using a laser guidewire (the European TOTAL Surveillance Study).

The success rates of coronary angioplasty for the treatment of chronic total occlusions are less favorable than for coronary stenosis. Therefore, a new laser guidewire (LW) was designed to facilitate the crossing of chronic total occlusions. We report on the results of a European multicenter surveillance study, evaluating the laser guidewire performance. Between May 1994 and July 1996, 345 patients (age 59 +/- 10 years, 291 men) with chronic total occlusions were enrolled in 28 European centers. The median age of occlusion was 29 weeks (range 2 to 884), the occlusion length 19 +/- 10 mm. LW recanalization was successful in 205 patients (59%/). LW perforation occurred in 73 patients (21%), with hemodynamic consequences in 4 (1%). There were no deaths, emergency coronary artery bypass graft surgery, or Q-wave myocardial infarctions. In a multivariate regression analysis an occlusion age of <40 weeks (p = 0.001, RR = 1.34) and an occlusion length <30 mm (p = 0.01, RR = 1.59) were independent predictors of success. Results indicate that the LW is an effective and safe tool in the treatment of chronic total occlusion refractory to conventional guidewires.

Chronic Disease↗
PubMed1997

Disturbed intracoronary hemodynamics in myocardial bridging: early normalization by intracoronary stent placement.

BACKGROUND: The purpose of this study was to evaluate the hemodynamic mechanisms leading to myocardial ischemia in patients with myocardial bridging. Myocardial bridging is known to induce angina and even severe myocardial ischemia. METHODS AND RESULTS: In 12 symptomatic patients with myocardial bridges, quantitative coronary angiography was performed to obtain systolic/diastolic vessel diameters within the bridged segments. Coronary flow velocities, flow reserve, and pressures were determined with a 0.014-in Doppler and a 0.014-in pressure microtransducer. In 3 symptomatic patients, coronary stents were implanted and hemodynamic measurements were repeated immediately and after 7 weeks. An in vitro validation of the pressure measurements was performed. Angiography revealed a systolic diameter reduction of 80.6+/-9.2% and a persistent diastolic reduction of 35.3+/-11% within the bridged segment. Diastolic flow velocities (cm/s) were increased (31.5+/-14.3 within versus 17.3+/-5.7 proximal and 15.2+/-6.3 distal, P<.001). Coronary flow reserve distal to the bridge was 2.5+/-0.5. There was an increased peak systolic pressure within the bridged segment (171+/-48 versus 113+/-10 mm Hg proximal, P<.001). Stent placement abolished the phasic lumen compression, the diastolic flow abnormalities, the intracoronary peak systolic pressure, and clinical symptoms. Coronary flow reserve improved to 3.8+/-0.3. CONCLUSIONS: Coronary hemodynamics in myocardial bridges are characterized by a phasic systolic vessel compression with a localized peak pressure, persistent diastolic diameter reduction, increased blood flow velocities, retrograde flow, and a reduced flow reserve. These alterations may explain the occurrence of symptoms and ischemia in these patients. Intracoronary stent placement abolished all hemodynamic abnormalities and may improve clinical symptoms in otherwise unsuccessfully treated patients with myocardial bridges.

Adult↗
PubMed1997

Quantitative analysis of the morphology of secundum-type atrial septal defects and their dynamic change using transesophageal three-dimensional echocardiography.

BACKGROUND: A noninvasive method for the determination of size and spatial relationships of atrial septal defects to adjacent cardiac structures, which would be advantageous to those contemplating device closure, is described. The aim of the study was to examine the value of transesophageal three-dimensional echocardiography for this purpose. METHODS AND RESULTS: Three-dimensional reconstruction of transesophageal two-dimensional echocardiography was performed in 17 patients. Left-to-right shunt (by oximetry in 16 of 17 patients) was 2.4 to 16.2 L/min, and the Qp/QS ratio was 1.4 to 4.7. The defect area of the atrial septal defect was measured throughout the whole cardiac cycle each 40 ms from the three-dimensional data set. Results were compared with shunt parameters by oximetry and with intraoperative measurements. Distances between atrial septal defect and mitral and tricuspid annulus and the orifices of the caval and pulmonary veins were also measured. The atrial septal defect area ranged from 0.2 to 2.4 cm2 (diastole) to 0.5 to 5.6 cm2 (systole). The maximal area at end-systole was 108% of the area at beginning of systole, and the minimal area at end-diastole was 43%. The defect area correlated significantly with the Qp/QS ratio (r=.70), and the maximal atrial septal defect diameters as measured by using three-dimensional echocardiography correlated well with intraoperative measurements (r=.87). Distances to mitral and tricuspid annulus and to the superior caval vein were determined in all patients. Distances to orifice of the inferior caval vein were measured in 12 patients, and orifices of right pulmonary veins were visible in 5 patients. CONCLUSIONS: Transesophageal three-dimensional echocardiography of atrial septal defects allows the determination of the instantaneous defect area and its dynamic changes and thus provides valuable information about the distances to adjacent cardiac structures. This may have clinical implications for the selection of patients suitable for interventional closure and for the assessment of procedural success.

Adult↗
PubMed1997

Frequency of deep vein thrombosis in patients with patent foramen ovale and ischemic stroke or transient ischemic attack.

To evaluate the additional value of transesophageal (TEE) compared with transthoracic (TTE) echocardiography and the role of patent foramen ovale (PFO) and deep vein thrombosis in the work-up of embolic events, patients with presumed cardiac embolic stroke or transient ischemic attack (neurovascular etiology was excluded) were prospectively studied by transthoracic and transesophageal contrast echocardiography. If PFO was detected echocardiographically, PFO size was assessed semiquantitatively and phlebography of both legs was performed. Two hundred forty-two consecutive patients (153 men, 60 +/- 15 years) were studied. In 197 patients, neuroimaging showed evidence of embolic infarction. TEE identified 138 potential cardiac sources of embolism in 111 patients, compared with 69 by TTE (p <0.01) in 59 patients. TEE detected potential cardiac sources in 52 patients with negative TTE examination and was significantly superior compared with TTE for identifying left atrial thrombi, spontaneous echo contrast, PFO, atrial septal aneurysm, and atheroma of the ascending aorta. In patients with a positive TTE, additional diagnostic information by TEE was found in only 6 patients and did not change therapy. Phlebography was performed in 53 patients with PFO and revealed deep vein thrombosis in 5 patients (9.5%); all had medium or large PFOs. Thus, in patients with cerebral ischemia of suspected cardiogenic origin and a normal TTE examination, TEE detects potential causes of embolism in 31% of patients and is therefore of diagnostic relevance. Conversely, in the presence of a diagnostic TTE an additional TEE confers only marginal diagnostic benefit. Deep venous thrombosis was detected in nearly 10% of patients with PFO as the sole identifiable cardiac risk factor. Given that in 4 of 5 patients deep vein thrombosis was clinically silent, phlebography should be performed in patients with medium or large interatrial shunts if paradoxical embolism is suspected.

Adult↗
PubMed1997

[3-D echocardiography: technical toy in search of a clinical application or logical evolution of diagnostic equipment?].

In recent years, 3D echocardiographic reconstruction and real time 3D echocardiography have been developed. Reconstruction techniques are based on one of two principles: acoustic or electromagnetic location devices that identify the spatial position of the transducer during imaging, or transducers that image from a fixed position varying the sector orientation in a predefined way. Animated, dynamic reconstructions of cardiac structures are possible, and the 3D data set can be sliced and viewed in any desired way after acquisition. The mitral annulus and congenital malformations of the heart have been imaged and studied successfully by 3D echo. Mass and volume calculations based on 3D data sets have been shown to be extraordinarily accurate by several investigators working with different techniques. Since the 3D data set is more comprehensive than any set of 2D images, such calculations are fundamentally superior to 2D or M-mode derived parameters. Color Doppler data can also be reconstructed into 3D data sets, with possible applications to proximal convergence zone calculations. However, broad implementation of 3D echo in clinical practice is hampered to date by cumbersome manual tracing to derive quantitative parameters and sometimes by insufficient image quality. Nevertheless, the rapid technical evolution, now including real-time 3D echo, ensures an important role for 3D echo in future echocardiography.

Cardiac Volume↗
PubMed1997

[Transesophageal Doppler echocardiography assessment of mitral valve insufficiency: Comparison of jet area, pulmonary venous flow profile, proximal jet diameter, maximal regurgitation flow rate and regurgitation orifice area with angiography].

UNLABELLED: In transesophageal echocardiography several methods have been used to grade mitral regurgitation. For a direct comparison of these techniques, 36 patients (60 +/- 13 years) with native mitral regurgitation underwent multiplane transesophageal echocardiography and angiography within 5 days. We compared the following measurements: 1) The maximal color jet area of mitral regurgitation, 2) the ratio of maximal systolic to diastolic pulmonary venous flow velocity in the left upper pulmonary vein, 3) the proximal jet width of mitral regurgitation, 4) the maximal regurgitant flow rate Qmax, measured by the proximal convergence method, 5) the regurgitant office area Areg, calculated by dividing Qmax by maximal regurgitant velocity obtained by continuous wave Doppler. RESULTS: The correlation between color jet area (r = 0.4; p < 0.05) or pulmonary venous flow (r = -0.3; p = n.s.) with angiographic severity of mitral regurgitation is low. The sensitivity of the retrospective best cut-off values is 69% (color jet area) and 83% (pulmonary venous flow). Using retrospective best cut-off values all patients with mitral regurgitation Sellers grade III and IV are correctly identified by a proximal jet width > or = 0.7 cm, Qmax > or = 300 ml/s or a Areg > or = 0.5 cm2 (sensitivity and specificity of 83-100%). Spearman's rank coefficient demonstrated a high correlation (r = 0.75-0.77; p < 0.001) between proximal jet width, Qmax and Areg and with angiographic severity. CONCLUSION: Multiplane transesophageal echocardiographic grading of mitral regurgitation by proximal jet width or proximal convergence zone shows comparably good results and is clearly superior to grading by color jet area or pulmonary venous flow, if adequate image quality is achieved.

Adult↗
PubMed1997

[Overestimation of regurgitation velocities of intact mechanical heart valve prostheses and other small orifices with 10 mm2 Doppler echocardiography].

A systematic evaluation of the accuracy of continuous wave echo Doppler measurements across prosthetic valve leakages and regurgitant lesions has not been performed. Continuous echo Doppler velocity measurements in an in vitro, steady flow model, across the leaks of 12 intact mechanical prostheses and across six circular nozzles (area, 0.5-20 mm2) at pressure drops between 30 and 105 mm Hg were analyzed and compared to the velocities predicted by the modified Bernoulli equation. Laser Doppler anemometry of flow velocities through the nozzles was performed in addition. Despite excellent correlation, there was substantial overestimation of "Bernoulli predicted"-velocities by echo Doppler in the prosthetic leaks (mean +12.3 +/- 9.4%; range, 90.3-143.4%). Also in nozzles < or = 10 mm2, but not in those > 20 mm2, an overestimation of the "Bernoulli predicted"-velocities was observed (mean +6.2 +/- 2%). Laser Doppler anemometry of flow velocities through the nozzles showed slightly lower values than predicted by the Bernoulli equation. This effect apparently is due to transit time effects leading to spectral broadening and should be taken into account when using echo Doppler measurements in very small (< 10 mm2) orifices, such as mild to moderate regurgitant lesions and prosthetic valve leakage.

Artifacts↗
PubMed1997

[Importance of endocardial ECG for successful AV-node modulation in patients with AV-node reentry tachycardia].

UNLABELLED: In 49 patients undergoing slow pathway (SP) ablation for AV nodal reentrant tachycardia (AVNRT) the local electrograms of successful and non-successful radiofrequency current applications taken from the mapping/ablation catheter in the posteroseptal space were retrospectively analyzed with respect to the following parameters: 1) ratio of local atrial (A) to local ventricular (V) electrogram amplitude (A/V-ratio), 2) presence of fractionated atrial activity (FAA) or SP potential (SPP), 3) duration of local A electrogram. Ablation sites were classified in 3 groups: group I: no FAA/SPP, A/V-ratio > or = 0.25; group 2: FAA/SPP or A/V-ratio < 0.25; group 3: FAA/SPP and A/V-ratio < 0.25. RESULTS: In all patients SP ablation was successful after 4.6 +/- 4.4 applications. Successful ablation sites had a significantly smaller A/V-ratio than non-successful ones (0.2 +/- 0.04 vs. 0.44 +/- 0.06, p = 0.023). The local A electrogram duration was not significantly different (72.3 +/- 2.14 vs. 71 +/- 1.35 ms, p = n. s.). CONCLUSIONS: 1) In SP ablation of AVNRT the local A/V-ratio is significantly smaller in successful compared to non-successful ablation sites. 2) Local A electrogram duration does not correlate with ablation success. 3) A local A/V-ratio of < 0.25 and the presence of a SPP or FAA are correlated with ablation success.

Adult↗
PubMed1997

Determination of left ventricular mass and circumferential wall thickness by three-dimensional reconstruction: in vitro validation of a new method that uses a multiplane transesophageal transducer.

Elevated left ventricular mass and increased wall thickness have important prognostic implications in clinical medicine. However, these parameters have been incompletely characterized by one- and two-dimensional echocardiography. Therefore this study was performed to validate in vitro measurement of left ventricular mass and circumferential wall thickness with a multiplane transesophageal transducer and three-dimensional reconstruction. Results for mass measurements were also compared with a standard method for the determination of left ventricular mass, the Penn convention. Fourteen necropsied left ventricles were scanned in a water bath by a volume-rendering, three-dimensional reconstruction system. There was an excellent correlation and high agreement for determination of three-dimensional left ventricular mass (r = 0.98; standard error of the estimate [SEE] = 9.6 gm; y = 1.02x + 0.46) and wall thickness (r = 0.93; SEE = 1.4 mm; y = 0.95x + 1.64) compared with anatomic measurements. Left ventricular mass by a simulated Penn convention revealed a lower correlation and larger error compared with three-dimensional measurements (r = 0.72; SEE = 42.8 gm; y = 1.01x + 9.61). Therefore determination of left ventricular mass by three-dimensional reconstruction was validated in vitro and was superior to one-dimensional echocardiographic methods.

Algorithms↗
PubMed1997

Angiotensin II receptor antagonist EXP 3174 reduces infarct size comparable with enalaprilat and augments preconditioning in the pig heart.

There is no agreement on the effect of angiotensin II receptor blockade in the setting of ischemic reperfusion. Our aim was to assess the acute effects of angiotensin-converting enzyme (ACE) inhibition and angiotensin II AT1-subtype receptor blockade in pig heart. Five groups of open-chest pigs received 1 hour of left anterior descending (LAD) coronary artery occlusion and 2 hours of reperfusion. Left ventricular pressure was monitored by an intraventricular catheter, and regional segment shortening (%SS) in the LAD-supplied territory was measured by ultrasonic crystals implanted in the subendocardium. Group 1 (n = 6) served as the control; groups 2 (n = 6) and 3 (n = 6) received the angiotensin II receptor blocker, EXP 3174 (C22H21Cl1N6O2), and the ACE inhibitor, enalaprilat, respectively, prior to LAD occlusion; group 4 (n = 6) was preconditioned with two cycles of 10 minutes of coronary occlusion and 30 minutes of reperfusion; and group 5 (n = 6) underwent preconditioning with additional administration of EXP 3174 prior to the 60-minute occlusion period. Infarct sizes were measured by p-nitrobluetetrazolium staining and were expressed in percent of the ischemic area of risk. The angiotensin II receptor blocker EXP 3174 and enalaprilat reduced infarct sizes significantly (35.3 +/- 17.1% and 40.1 +/- 15.1%, respectively) compared with controls (71.2 +/- 12.8%, P < 0.05), and EXP 3174 augmented the infarct size-limiting effects of preconditioning by ischemia (10.5 +/- 6% vs. 28.6 +/- 5.3%, P < 0.05). Regional contractile dysfunction during reperfusion demonstrated no changes after angiotensin II receptor blockade. Angiotensin II receptor blockade reduced infarct size comparable with that obtained with angiotensin converting-enzyme inhibition. The infarct size-limiting effects of ischemic preconditioning were augmented by administration of the angiotensin II receptor antagonist EXP 3174. These data support the concept that blockade or inhibition of angiotensin II before coronary occlusion is protective in a swine model of acute ischemia and reperfusion.

Angiotensin Receptor Antagonists↗
PubMed1997

Transoesophageal stress echocardiography.

Transoesophageal echocardiography has been performed in conjunction with pacing, dobutamine, or dipyridamole stress to detect stress-inducible ischaemia, and has proved to be a highly accurate diagnostic tool. Its advantages of improved image quality and high diagnostic accuracy have to be weighed against the disadvantages of semi-invasiveness and patient discomfort. The existing data on this stress echo modality and on special applications (diastolic dysfunction, ischaemic mitral regurgitation, hibernating myocardium, peri-operative risk assessment) are reviewed.

Angioplasty, Balloon, Coronary↗