The optimal management of cardioversion of atrial fibrillation or flutter: still a 'stunning' problem.
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Anticoagulants↗
Biomedical subjects
P Hanrath
Publications and source records attributed to P Hanrath.
Rapid quantification of left ventricular function and mass using transoesophageal three-dimensional echocardiography: validation of a method that uses long-axis cutplanes.
AIMS: Despite its proven superiority compared to conventional echocardiographic techniques, three-dimensional (3D) echocardiography has not gained widespread acceptance in clinical medicine for the quantification of left ventricular volumes, function and mass. This is mainly due to the large, time-consuming process of data analysis. We sought to validate a new method that enables the accurate quantification of the left ventricle in a clinically acceptable short period of time. METHODS AND RESULTS: Left ventricular volumes, ejection fraction and mass were determined in 44 patients using 3D echocardiography. The 3D echocardiographic data sets were analysed: (i) using the conventional 'summation of slices' algorithm (slice thickness 5 and 10mm), which is based on the analysis of the 3D reconstructed left ventricle in short-axis cross-sections; and (ii) using the new method which is based on the analysis of the 3D reconstructed left ventricle in long-axis images. In each patient measurements were repeated using 3, 6, 7, 8, 9, 12 and 15 long-axis images. For all volumetric measurements there was a continuous reduction of measurement variability using increasing numbers of long-axis images. The use of more than nine long-axis images for volumes, and eight long-axis images for ejection fraction and mass, did not result in a further reduction of variability. The analysis time for volumes and masses averaged less than 5 min for the long-axis method using nine component images, compared to 20-43 min for the short-axis method. CONCLUSION: 3D echocardiography combined with a novel method based on the analysis of long-axis cross-section allows accurate quantification of left ventricular volumes, function and mass in a clinically acceptable short period of time. In the future, the combination of a real-time 3D echocardiographic acquisition technique with this analysis method should have important implications for the introduction of 3D echocardiography in clinical practice.
Echocardiography, Three-Dimensional↗
Analysis of shape and motion of the mitral annulus in subjects with and without cardiomyopathy by echocardiographic 3-dimensional reconstruction.
The shape and dynamics of the mitral annulus of 10 patients without heart disease (controls), 3 patients with dilated cardiomyopathy, and 5 patients with hypertrophic obstructive cardiomyopathy and normal systolic function were analyzed by transesophageal echocardiography and 3-dimensional reconstruction. Mitral annular orifice area, apico-basal motion of the annulus, and nonplanarity were calculated over time. Annular area was largest in end diastole and smallest in end systole. Mean areas were 11.8 +/- 2.5 cm(2) (controls), 15.2 +/- 4.2 cm(2) (dilated cardiomyopathy), and 10.2 +/- 2.4 cm(2) (hypertrophic cardiomyopathy) (P = not significant). After correction for body surface, annuli from patients with normal left ventricular function were smaller than annuli from patients with dilated cardiomyopathy (5.9 +/- 1.2 cm(2)/m(2) vs 7.7 +/- 1.0 cm(2)/m(2); P <.02). The change in area during the cardiac cycle showed significant differences: 23.8% +/- 5.1% (controls), 13.2% +/- 2.3% (dilated cardiomyopathy), and 32.4% +/- 7.6% (hypertrophic cardiomyopathy) (P <.001). Apico-basal motion was highest in controls, followed by those with hypertrophic obstructive and dilated cardiomyopathy (1.0 +/- 0.3 cm, 0.8 +/- 0.2 cm, 0.3 +/- 0.2 cm, respectively; P <.01). Visual inspection and Fourier analysis showed a consistent pattern of anteroseptal and posterolateral elevations of the annulus toward the left atrium. In conclusion, although area changes and apico-basal motion of the mitral annulus strongly depend on left ventricular systolic function, nonplanarity is a structural feature preserved throughout the cardiac cycle in all three groups.
Adult↗
Severe transmyocardial ischemia in a patient with tension pneumothorax.
OBJECTIVE: To report tension pneumothorax (TP) as a cause of severe myocardial ischemia. DESIGN: Clinical case report. SETTING: Medical intensive care unit of a university hospital. PATIENTS: One patient with severe shock attributable to right TP after unsuccessful percutaneous central venous catheterization. INTERVENTIONS: Blood pressure, electrocardiogram (ECG), chest radiograph, and echocardiography during and after shock. MEASUREMENTS AND MAIN RESULTS: On admission the patient was in profound state of shock (heart rate 140 beats/min, blood pressure 65/30 mm Hg). Twelve-lead ECG showed pronounced ST segment elevation in leads II, III, aVF, and V4-V6. Chest radiograph revealed right TP with complete displacement of the mediastinum and the heart to the left side. Immediate right-sided tube thoracostomy resulted in reexpansion of the lung followed by instantaneous hemodynamic and respiratory improvement as well as nearly complete resolution of the ECG changes. Peak value of the creatine phosphokinase was 4140 U/L without significant elevation of the MB isoenzyme at any time. Moreover, the initial hypokinesia of the posterior and lateral left ventricular wall resolved completely, as demonstrated by echocardiography. CONCLUSION: The specific condition of TP may lead to impaired systolic and diastolic coronary artery blood flow affecting ventricular repolarization and T-wave configuration in ECG indicative of transmyocardial ischemia. General symptoms, namely hypotension, tachycardia, and hypoxemia, are likewise typical for cardiogenic shock attributable to myocardial infarction. Yet any therapeutic measure directed toward revascularization, such as thrombolysis or even percutaneous transluminal coronary angioplasty, would have had devastating consequences. Therefore, thorough physical examination of our patient was pivotal in disclosing the true origin of profound shock.
Aged↗
Gastric tonometry in patients with cardiogenic shock and intra-aortic balloon counterpulsation.
OBJECTIVE: To study the course of gastric regional PCO2 (PrCO2) in patients with cardiogenic shock requiring intra-aortic balloon (IAB) counterpulsation and the prognostic value of PrCO2 in this patient population. DESIGN: A prospective, observational clinical study. SETTING: Medical intensive care unit in a university hospital. PATIENTS: Twenty-six consecutive patients with cardiogenic shock requiring mechanical support with an IAB counterpulsation undergoing mechanical ventilation INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULT: Hemodynamic variables, tonometric variables, arterial blood gases, and arterial lactate were assessed before insertion of IAB (baseline), and 1, 2, 3, 8, 16, 24, and 48 hrs thereafter. A subset of these patients (n = 14) were studied just before and 1, 8, 24, and 32 hrs after IAB removal; 12/26 patients (46.2%) died. Cardiac index increased from baseline to 1 hr after insertion of IAB (1.7 +/- 0.3 to 2.6 +/- 0.8 L/min/m2, p < .05). PrCO2 did not change between admission (47 +/- 13 torr [6.3 +/- 1.7 kPa]) and 8 hrs after placement of IAB but increased to 63 +/- 22 torr (8.4 +/- 2.9 kPa) at 16 hrs (p < .05) without any further alteration until 48 hrs. CO2 gap showed a similar pattern with 15 +/- 11 torr (2.0 +/- 1.5 kPa) at baseline and an increase to 28 +/- 22 torr (3.7 +/- 2.9 kPa) 16 hrs later. PrCO2 and CO2 gap remained at high levels (59 +/- 11 torr [7.7 +/- 1.5 kPa] and 22 +/- 10 torr [2.9 +/- 1.3 kPa], respectively), before IAB removal without further improvement or deterioration thereafter. PrCO2 values showed no difference between survivors and nonsurvivors at any time point. CONCLUSION: Patients with cardiogenic shock developed high PrCO2 within the first 24 hrs, which reflects gastric mucosal ischemia. Persistently high levels of PrCO2 were indicative for prolonged hypoperfusion of the gut. Gastric tonometry failed to discriminate between survivors and nonsurvivors.
Aged↗
Non-contrast second harmonic imaging improves interobserver agreement and accuracy of dobutamine stress echocardiography in patients with impaired image quality.
OBJECTIVE: To examine the influence of second harmonic imaging during dobutamine echocardiography on regional endocardial visibility, interobserver agreement in the interpretation of wall motion abnormalities, and diagnostic accuracy in patients with reduced image quality. DESIGN: Blinded comparison. SETTING: Tertiary care centre. PATIENTS: 103 consecutive patients with suspected coronary artery disease and impaired transthoracic image quality (>/= 2 segments with poor endocardial delineation). METHODS: Fundamental and second harmonic imaging were performed at each stage of a dobutamine stress echocardiography. Coronary angiography was undertaken within three weeks of dobutamine echocardiography in 75 patients. MAIN OUTCOME MEASURES: Evaluation of regional endocardial visibility (scoring from 0 = poor to 2 = good) and of segmental wall motion abnormalities for both modalities separately. A second blinded examiner analysed 70 studies to determine interobserver agreement. RESULTS: Mean (SD) visibility score for all segments was 1.2 (0.4) using fundamental imaging and 1.7 (0.2) using second harmonic imaging at rest (p < 0.001), and 1.1 (0.4) v 1.6 (0.3), respectively, at peak dobutamine dose (p < 0.001). The average number of segments with poor endocardial visibility was lower for second harmonic than for fundamental imaging (0.6 (1.1) v 3.8 (2.6) at rest, p < 0.001; 0.9 (1.3) v 4.3 (2.9) at peak dose, p < 0.001). Improvement was most pronounced in all lateral and anterior segments. The kappa value for identical study interpretation increased from 0. 40 to 0.69 (p < 0.05). Sensitivity for the diagnosis of coronary artery disease was 64% using fundamental imaging versus 92% using harmonic imaging (p < 0.001), while specificity remained unchanged at 75% for both imaging modalities. CONCLUSIONS: Second harmonic imaging enhances endocardial visibility during dobutamine echocardiography. Consequently, interobserver agreement on stress echocardiography interpretation and diagnostic accuracy are significantly improved compared to fundamental imaging. Thus, in difficult to image patients, dobutamine echocardiography should be performed using second harmonic imaging.
Cardiotonic Agents↗
Long term angiographic and clinical follow up in patients with stent implantation for symptomatic myocardial bridging.
OBJECTIVE: To assess long term results of coronary stent implantation in patients with symptomatic myocardial bridging. METHODS: Intracoronary stent implantation was performed within the intramural course of the left anterior descending coronary artery in 11 patients with objective signs of myocardial ischaemia and absence of other cardiac disorders. All had myocardial bridging of the central portion of the left anterior descending coronary artery. Quantitative coronary angiography was performed before and after stent deployment, and again at seven weeks and six months. Clinical evaluation was done at two years. RESULTS: After stent deployment, quantitative coronary angiography showed absence of systolic compression along the left anterior descending coronary artery; the minimum luminal diameter (mean (SD)) increased from 0.6 (0.3) mm before stent implantation to 1.9 (0.3) mm after implantation (p < 0. 05). Intravascular ultrasound showed an increase in cross sectional area from 3.3 (1.3) mm(2) at baseline to 6.8 (0.9) mm(2) (p < 0.005) after stent deployment. Coronary flow reserve was normalised from 2. 6 (0.5) at baseline to 4.0 (0.5) (p < 0.005) after stent implantation. At seven weeks, quantitative coronary angiography showed mild to moderate or severe in-stent stenosis in five of the 11 patients; four of these underwent repeat target vessel revascularisation (percutaneous transluminal coronary angioplasty in two; coronary artery bypass grafting in two). At six months, all patients (n = 9) showed good angiographic results, including those who had target vessel revascularisation. On clinical evaluation at two years, all patients (including those with target vessel revascularisation) remained free of angina and cardiac events. CONCLUSIONS: Intracoronary stent implantation prevents external compression of bridged coronary artery segments, with increase in luminal diameter and alleviation of symptoms. The incidence of in-stent stenosis requiring target vessel revascularisation (36%) is comparable with that of lesions of 25 mm length in coronary artery disease. The symptom free and event free two year follow up data suggest that stent implantation is a useful way of treating symptomatic patients with myocardial bridges.
Adult↗
Changes of beta-adrenergic signaling in compensated human cardiac hypertrophy depend on the underlying disease.
In human heart failure, desensitization of the beta-adrenergic signal transduction has been reported to be one of the main pathophysiological alterations. However, data on the beta-adrenergic system in human compensated cardiac hypertrophy are very limited. Therefore, we studied the myocardial beta-adrenergic signaling in patients suffering from hypertrophic obstructive cardiomyopathy (HOCM, n = 9) or from aortic valve stenosis (AoSt, n = 8). beta-Adrenoceptor density determined by [(125)I]iodocyanopindolol binding was reduced in HOCM and AoSt compared with nonhypertrophied, nonfailing myocardium (NF) of seven organ donors. In HOCM the protein expression of stimulatory G protein alpha-subunit (G(s)alpha) measured by immunoblotting was unchanged, whereas the inhibitory G protein alpha-subunit (Galpha(i-2)) was increased. In contrast, in AoSt, Galpha(i-2) protein was unchanged, but G(s)alpha protein was increased. Adenylyl cyclase stimulation by isoproterenol was reduced in HOCM but not in AoSt. Plasma catecholamine levels were normal in all patients. In conclusion, both forms of hypertrophy are associated with beta-adrenoceptor downregulation but with different changes at the G protein level that occur before symptomatic heart failure due to progressive dilatation of the left ventricle develops and are not due to elevated plasma catecholamine levels.
Adaptation, Physiological↗
Transesophageal 3-dimensional echocardiography: in vivo determination of left ventricular mass in comparison with magnetic resonance imaging.
The objective of this study was to assess the accuracy and reproducibility of transesophageal 3-dimensional echocardiography (3DE) in comparison with magnetic resonance imaging (MRI) for the in vivo calculation of left ventricular mass (LVM). In addition, mass values obtained by M-mode echocardiography were compared with those calculated by MRI. Three-dimensional reconstruction of the left ventricle was performed from a transesophageal and transgastric transducer position with a multiplane transducer in 20 patients. Left ventricular mass was calculated from both transducer positions by using slices of various thicknesses, ranging from 5 to 20 mm. Reproducibility was determined by 5 repeated measurements of mass in each of 5 randomly selected left ventricles. M-mode echocardiography was performed according to the method described by Devereux. For MRI, multiple short-axis views with 10-mm slice thickness were acquired in inspiration hold. Correlation was high for mass determined by 3DE and MRI (for 10-mm slice thickness: r = 0.99; y = 0.99 x - 0.7 g; standard error of estimate = 8.5 g; P <.001). There was no statistical bias, and the limits of agreement ranged from +/-16.4 g to +/-27.2 g, depending on the slice thickness. Variability was lowest for a slice thickness of 10 mm (SD +/- 8.2 g). The reproducibility of mass determination was excellent (mean width of the 95% CI 12.8 g). Left ventricular mass values calculated from the transgastric and transesophageal transducer position were not different from each other (mean bias 0.6 +/- 9.1 g; P = ns). M-mode-based LVM calculations showed systematic overestimation and large measurement variability (bias 23.7 g; 95% CI +/- 92.8 g). Compared with MRI, transesophageal 3DE is an accurate and reproducible method for the determination of LVM and clearly superior to M-mode echocardiography.
Adult↗
[Catheter ablation of accessory pathways and atrioventricular nodal reentry tachycardia].
Radiofrequency current catheter ablation has gained acceptance as primary long-term therapy for patients with symptomatic accessory pathways and symptomatic atrioventricular nodal reentrant tachycardia (AVNRT) with frequent recurrences. In both arrhythmias, curative treatment is possible in more than 90% of cases at a low complication rate although an incidence of about 1% complete AV block after slow pathway ablation has to be taken into account when this therapy is considered. The recurrence rate is 3-10% for accessory pathways and 0-15% for AVNRT. The high success rate of catheter ablation has already led to a shift in the indications for the procedure where the percentage of patients with accessory pathways is decreasing and there is an increase of patients with AVNRT and newer indications (atrial flutter, focal atrial tachycardias).
Catheter Ablation↗
Transthoracic echocardiography using second harmonic imaging: diagnostic alternative to transesophageal echocardiography for the detection of atrial right to left shunt in patients with cerebral embolic events.
OBJECTIVES: We sought to evaluate whether transthoracic contrast echocardiography using second harmonic imaging (SHI) is a diagnostic alternative to transesophageal contrast echocardiography (TEE) for the detection of atrial right to left shunt. BACKGROUND: Paradoxic embolism is considered to be the major cause of cerebral ischemic events in young patients. Contrast echocardiography using TEE has proven to be superior to transthoracic echocardiography (TTE) for the detection of atrial shunting, SHI is a new imaging modality that enhances the visualization of echocardiographic contrast agents. METHODS: We evaluated 111 patients with an ischemic cerebral embolic event for the presence of atrial right to left shunt using an intravenous (IV) contrast agent in combination with three different echocardiographic imaging modalities: 1) TTE using fundamental imaging (FI); 2) TTE using SHI; and 3) TEE. The severity of atrial shunting and the duration of contrast visibility within the left heart chambers were evaluated for each imaging modality. Image quality was assessed separately for each modality by semiquantitative scoring (0 = poor to 3 = excellent). Presence of atrial right to left shunt was defined as detection of contrast bubbles in the left atrium within the first three cardiac cycles after contrast appearance in the right atrium either spontaneously or after the Valsalva maneuver. RESULTS: A total of 57 patients showed evidence of atrial right to left shunt with either imaging modality. Fifty-one studies were positive with TEE, 52 studies were positive with SHI, and 32 were positive with FI (p<0.001 for FI vs. SHI and TEE). The severity of contrast passage was significantly larger using SHI (61.6+/-80.2 bubbles) compared to FI (53.7+/-69.6 bubbles; p<0.005 vs. SHI) but was not different compared to TEE (43.9+/-54.3 bubbles; p = NS vs. SHI). The duration of contrast visibility was significantly longer for SHI (17.4+/-12.4 s) compared to FI (13.1+/-9.7 s; p<0.001) and TEE (11.9+/-9.6 s; p<0.02). Mean image quality improved significantly from FI (1.5+/-0.8) to SHI (2.0+/-0.8; p<0.001 vs. FI) and TEE (2.5+/-0.7; p<0.001 vs. SHI). CONCLUSIONS: In combination with IV contrast injections, TEE and SHI have a comparable yield for the detection of atrial right to left shunt. Both modalities may miss patients with atrial shunting. In young patients with an unexplained cerebrovascular event and no clinical evidence of cardiac disease, a positive SHI study may obviate the need to perform a TEE study to search for cardiac sources of emboli.
Adult↗
[The value of echocardiography for the assessment of chronic mitral valve insufficiency].
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Chronic Disease↗
[Medical care in the Federal Republic of Germany with special consideration of cardiology as a priority subject. Current state and prospects].
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Cardiology↗
[Evidence based medicine using heart failure as a paradigm].
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Adrenergic beta-Antagonists↗
Spatial features in body surface potential maps of patients with ventricular tachyarrhythmias with or without coronary artery disease.
Body surface potential maps (BSPM) from patients with coronary artery disease or no structural heart disease were analyzed with respect to their spatial features and QT/QTc dispersion in order to determine whether BSPM allows identification of patients with ventricular fibrillation. QRST integral maps and QT/QTc dispersion were acquired from simultaneous recordings of 62 ECG leads during sinus rhythm in patients with idiopathic ventricular fibrillation (n=13), ventricular fibrillation and coronary artery disease (n=22), coronary artery disease without ventricular fibrillation (n=21) and healthy controls (n=18). The Karhunen-Loeve transformation was applied to reduce the dimensionality of the data matrix of the QRST map to eight coefficients. Linear discriminant analysis allowed discrimination between idiopathic ventricular fibrillation patients and controls with high sensitivity (85%) and specificity (89%). However, discrimination between coronary artery disease patients with or without ventricular fibrillation was poor (68% and 67%, respectively). QTc dispersion calculated from BSPM was longer in idiopathic ventricular fibrillation patients than in controls (99+/-30 ms vs 70+/-14 ms, P=0.009) in contrast to QTc dispersion taken from 12-lead ECG (53+/-21 ms vs. 47+/-12 ms, P=n.s.). No significant difference was noted for coronary artery disease patients with or without ventricular fibrillation. In conclusion, repolarization disturbances detected by BSPM allow identification of ventricular fibrillation patients without structural heart disease. However, our results do not suggest a major impact of QT/QTc dispersion or QRST integral mapping for identification of ventricular fibrillation patients with coronary artery disease.
Body Surface Potential Mapping↗
[Polymorphisms--genetic risk factors for coronary heart disease?].
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Blood Coagulation↗
[Anticoagulation in atrial fibrillation before cardioversion].
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Anticoagulants↗
Effect of biphasic shock duration on defibrillation threshold with different electrode configurations and phase 2 capacitances: prediction by upper-limit-of-vulnerability determination.
BACKGROUND: The defibrillation threshold (DFT) may be affected by biphasic shock duration (BSD), electrode configuration, and capacitance. The upper limit of vulnerability (ULV) may be used to estimate the DFT. For different lead configurations and phase 2 capacitances, we investigated in 18 pigs whether the use of ULV may predict waveforms with lowest DFT. METHODS AND RESULTS: -DFT and ULV were determined by up-down protocols for 10 BSDs. ULVs were measured by T-wave scanning during ventricular pacing (cycle length 500 ms). In protocol 1 (n=6), a pectoral "active can" was combined with an electrode in the superior vena cava as common cathode and a right ventricle electrode as anode (AC+SVC). In protocol 2 and protocol 3 (n=6 each), only the "active can" was used as proximal electrode (AC). Capacitance was 150 microF during both phases in protocol 1 and protocol 3 but 150 microF (phase 1) and 300 microF (phase 2) in protocol 2. ULV and DFT demonstrated a linear correlation in each protocol (r=0.78 to 0.84). Lowest DFTs were found at 10 ms for AC+SVC and at 14 ms for AC (P<0.001). At optimal BSDs, voltage DFTs did not differ significantly between AC (527+/-57 V) and AC+SVC (520+/-70 V). Switching capacitors for phase 2 in a way that reduced leading-edge voltage by 50% while doubling capacity did not change BSD for optimal voltage DFT but increased minimum DFT from 527+/-57 V to 653+/-133 V (P=0.04). CONCLUSIONS: The BSD with lowest DFT is shorter for AC+SVC than for AC. There is no significant difference in voltage DFT between both at optimal BSD. A lower phase 2 capacitance reduces DFTs irrespective of BSD. Because strength-duration curves for DFT and ULV correlate for different BSDs, lead systems, and phase 2 capacitances, ULV determination may allow the prediction of waveforms with lowest DFT.
Animals↗