Instrument for investigating regulation of cardiac output with automatic pressure stabilization of left ventricular outflow

1967 ◽  
Vol 64 (3) ◽  
pp. 1025-1027
Author(s):  
M. M. Povzhitkov
Keyword(s):  
Cardiac Output ◽  
Left Ventricular ◽  
Automatic Pressure ◽  
Left Ventricular Outflow ◽  
Pressure Stabilization

Beta blocker therapy in recipients of twin-to-twin transfusion syndrome

2018 ◽  
Vol 104 (5) ◽  
pp. F541-F543
Author(s):  
Kerstin Gruendler ◽  
Christoph E Schwarz ◽  
Laila Lorenz ◽  
Christian F Poets ◽  
Axel R Franz
Keyword(s):  
Cardiac Output ◽  
Beta Blocker ◽  
Left Ventricular Outflow Tract ◽  
Myocardial Hypertrophy ◽  
Ventricular Outflow Tract ◽  
Left Ventricular ◽  
Outflow Tract ◽  
Circulatory Support ◽  
Low Cardiac Output ◽  
Left Ventricular Outflow

Recipients of severe twin-to-twin transfusion syndrome (TTTS) may suffer from low cardiac output caused by myocardial hypertrophy and sudden postnatal drop in preload. Our hypothesis was that selective beta-1 adrenergic blockers improve cardiac function in TTTS recipients with left ventricular outflow tract obstruction. We analysed data from two TTTS recipients treated with esmolol/metoprolol. Despite intense circulatory support, both patients showed severe hypotension and tachycardia before therapy. Echocardiographic findings included hypertrophic ventricles with thickened intraventricular septum, reduced aortic valve velocity time integral (AV-VTI), left ventricular outflow tract obstruction and collapsing ventricles in systole. Beta blocker improved blood pressure as well as AV-VTI, which served as a surrogate parameter for left ventricular stroke volume, reduced heart rate and need for circulatory support. In conclusion, beta blockade may improve left ventricular function in TTTS recipients with low cardiac output due to myocardial hypertrophy.

scholarly journals Correlation between QRS duration and cardiac output measured by left ventricular outflow tract velocity in patient with cardiac resynchronization therapy

QJM ◽  
2020 ◽  
Vol 113 (Supplement_1) ◽  
Author(s):  
A S A E Elshikh ◽  
M M Khalifa ◽  
H Shehata ◽  
A Murtada
Keyword(s):  
Heart Failure ◽  
Cardiac Output ◽  
Left Ventricular Outflow Tract ◽  
Ventricular Outflow Tract ◽  
Left Ventricular ◽  
Cardiac Resynchronization ◽  
Resynchronization Therapy ◽  
Left Ventricular Outflow ◽  
Qrs Duration ◽  
Post Implantation

Abstract Background Cardiac resynchronization therapy (CRT) is proved as an effective treatment for moderate to severe heart failure. It reduces all-cause mortality in patients with advanced heart failure. There is strong evidence that CRT reduces mortality and hospitalization, improves cardiac function and structure in symptomatic chronic heart failure patients with optimal medical treatment, severely depressed LVEF (i.e. <35%) and complete LBBB. However 30% of patients may show negative response to CRT therapy. Therefore, optimization of CRT therapy in patients with heart failure seems to be a main subject for study in our researches. Methods of optimization includes optimization of medical therapy, control of risk factors and comorbidities, and optimization of device implantation and programming. Overall, studying the correlation between QRS duration and cardiac output will improve CRT programming optimization techniques. Aim To study the correlation between QRS duration and cardiac output measured by left ventricular outflow tract (LVOT) VTI in patients with CRT implantation. Methods Study included 100 CRT already implanted patients, they are requested to do a simple electrocardiographic and echocardiographic study. The relation between post implant QRS and cardiac output are studied among the patients. Results There was negative significant correlation between QRS duration and LVOT VTI and SVi. The optimal cut off values for optimal response to CRT using ROC curves were 130msec for post implant QRS duration and 17.1 cm for LVOT VTI. Conclusion CRT response is more in female patients with lower BSA, and without previous history of IHD or smoking. There is a significant negative correlation between QRS duration and LVOT VTI. Post implantation cut off value of QRS duration (<130) predict higher LVOT VTI and also the post implantation benefit for the patient with CRT implanted.

Intraoperative Determination of Cardiac Output Using Multiplane Transesophageal Echocardiography 

1998 ◽  
Vol 89 (2) ◽  
pp. 350-357 ◽  
Author(s):  
Albert C. Perrino ◽  
Stephen N. Harris ◽  
Martha A. Luther
Keyword(s):  
Cardiac Output ◽  
Transesophageal Echocardiography ◽  
Continuous Wave ◽  
Left Ventricular Outflow Tract ◽  
Ventricular Outflow Tract ◽  
Left Ventricular ◽  
Outflow Tract ◽  
Continuous Wave Doppler ◽  
Imaging Array ◽  
Left Ventricular Outflow

Background Limitations in the imaging views that can be obtained with transesophageal echocardiography (TEE) have hindered development of a widely adopted Doppler method for cardiac output (CO) monitoring. The authors evaluated a CO technique that combines steerable continuous-wave Doppler with the imaging capabilities of two-dimensional multiplane TEE. Methods From the transverse plane transgastric, short-axis view of the left ventricle, the imaging array was rotated to view the left ventricular outflow tract (LVOT) and ascending aorta. Steerable continuous-wave Doppler was subsequently used to measure aortic blood flow velocities. Aortic valve area was determined using a triangular orifice model. Matched thermodilution and Doppler CO measurements were obtained serially during surgery. Results The left ventricular outflow tract was imaged in 32 of 33 patients (97%). Data analysis reveal a mean difference between techniques of -0.01 l/min, and a standard deviation of the differences of 0.56 l/min. Multiple regression showed a correlation of r = 0.98 between intrasubject changes in CO. Multiplane TEE correctly tracked the direction of 37 of 38 serial changes in thermodilution CO but with a modest 14% underestimation of the magnitude of these changes. Conclusions These results indicate that multiplane TEE can provide an alternative method for the intraoperative measurement of CO. The ability of the rotatable imaging array to align with the left ventricular outflow tract and the need for only minimal adjustments in probe position advance the utility of intraoperative TEE.

Cardiac output response and peripheral oxygen extraction during exercise among symptomatic hypertrophic cardiomyopathy patients with and without left ventricular outflow tract obstruction

Heart ◽  
2014 ◽  
Vol 100 (8) ◽  
pp. 639-646 ◽  
Author(s):  
Christopher H Critoph ◽  
Vimal Patel ◽  
Bryan Mist ◽  
Perry M Elliott
Keyword(s):  
Cardiac Output ◽  
Oxygen Consumption ◽  
Hypertrophic Cardiomyopathy ◽  
Cardiac Index ◽  
Left Ventricular Outflow Tract ◽  
Ventricular Outflow Tract ◽  
Left Ventricular ◽  
Non Invasive ◽  
Left Ventricular Outflow ◽  
Oxygen Difference

ObjectiveReduction of left ventricular outflow tract obstruction (LVOTO) often improves symptoms in hypertrophic cardiomyopathy (HCM), but the correlation between exercise performance and measured LVOT gradients is weak. We investigated the relationship between LVOTO and cardiorespiratory responses during exercise.MethodsThe study cohort included 70 patients with HCM (32 with LVOTO, 55 male, age 47±13) attending a dedicated cardiomyopathy clinic and 28 normal volunteers. All underwent cardiopulmonary exercise testing with simultaneous non-invasive haemodynamic assessment using finger plethysmography. Main outcome measures were peak oxygen consumption, cardiac index and arteriovenous oxygen difference.ResultsWhen compared with controls, patients had reduced peak exercise oxygen consumption (22.4±6.1 vs 34.7±7.7 mL/kg/min, p<0.0001) and cardiac index (5.5±1.9 vs 9.4±2.9 L/min/m2, p<0.0001). At all workloads, stroke volume index (SVI) was lower and arteriovenous oxygen difference greater in patients. During all stages of exercise, LVOTO in patients was associated with failure to augment SVI and higher oxygen consumption; cardiac reserve (4.4±2.7 vs 6.3±3.6 L/min, p=0.025) and peak mean arterial pressure (104±16 vs 112±16 mm Hg, p=0.033) were lower. Multivariable predictors of cardiac output response were age (β: −0.11; CI −0.162 to −0.057; p<0.0001), peak LVOT gradient (β: −0.018; CI −0.034 to −0.002; p=0.031) and gender (β: −2.286; CI −0.162 to −0.577; p=0.01). Within the obstructive cohort, different patterns of SV response were elicited in patients with similar clinical features.ConclusionsCardiac reserve is reduced in HCM because of failure of SV augmentation. LVOTO exacerbates this abnormal response, but haemodynamic responses vary significantly. Non-invasive exercise haemodynamic assessment may improve understanding of symptoms and help tailor therapy.

scholarly journals Can Left ventricular outflow tract aortic velocity time integral guide fluid resuscitation in septic patients? - A case report

2020 ◽  
Vol 16 (2) ◽  
Author(s):  
Livio Colombo ◽  
Francesco Panizzardi ◽  
Irene Rusconi ◽  
Anna Roncoroni ◽  
Marta Bergamaschi ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Case Report ◽  
Left Ventricular Outflow Tract ◽  
Venous Pressure ◽  
Ventricular Outflow Tract ◽  
Left Ventricular ◽  
Outflow Tract ◽  
Velocity Time Integral ◽  
Time Integral ◽  
Left Ventricular Outflow

Hemodynamic monitoring of unstable patients is an everyday issue for Emergency Physicians (EP). Considering the difficulty, in Emergency Department (ED) settings, to assess invasively Stroke Volume (SV), Cardiac Output (CO) and Peripheral Vascular Resistance (PVR), EP should be familiar with non-invasive, easy and reproducible methods that can estimate these parameters. The use of Left Ventricular Outflow Tract aortic Velocity Time Integral (LVOT-VTI) with echocardiography, as estimate of SV, integrated with inferior vena cava collapse index and clinical examination could give the opportunity to non-invasively understand at which point of an ideal cardiac output/central venous pressure relation (according to the Frank Starling law) the patient is situated. In this case report we describe a septic patient accessing the ED with both respiratory and cardiac failure, and we show that the use of aortic LVOT-VTI is an easy and reproducible approach to understand cardiac hemodynamic in scenarios involving multiple pathologic mechanisms.

scholarly journals Estimation of Cardiac Output by Noninvasive Echocardiographic Techniques in the Critically Ill Subject

1997 ◽  
Vol 25 (3) ◽  
pp. 250-254 ◽  
Author(s):  
A. S. McLean ◽  
A. Needham ◽  
D. Stewart ◽  
R. Parkin
Keyword(s):  
Cardiac Output ◽  
Critically Ill ◽  
Ventricular Outflow Tract ◽  
Left Ventricular ◽  
Chamber Method ◽  
Doppler Method ◽  
Prospective Comparison ◽  
Left Ventricular Outflow ◽  
Method R ◽  
Acceptable Agreement

We evaluated the accuracy of cardiac output estimations by three transthoracic echocardiographic techniques in critically ill subjects. This study was a prospective comparison study carried out in a general intensive care unit of a teaching hospital. The subjects had a broad range of diagnoses including pulmonary embolus, cardiogenic shock, septic shock, Legionnaire's disease and perioperative myocardial infarction. All patients requiring pulmonary artery catheterization underwent echocardiographic cardiac assessment with comparison of findings to those obtained by thermodilution techniques. Nineteen studies on eighteen patients were performed, with cardiac output calculated by the two-chamber Simpson's, four-chamber Simpson's, and left ventricular outflow tract (LVOT) Doppler methods. Acceptable data was obtained in those patients without mitral regurgitation. There was good correlation between the thermodilution technique and Simpson's two-chamber method (r=0.91), but less so with the Simpson's four-chamber method (r=0.77). All studies were included in the LVOT Doppler method with a good correlation (r=0.94). A plot of differences between methods using the Bland and Altman statistical method indicated that only the LVOT Doppler method demonstrated acceptable agreement with a mean of 0.2 litres/minute, standard deviation of 0.82 litres/minute and 95% limits of agreement of –1.5 to +1.9 litres/minute. We concluded that the LVOT Doppler method was the only one which demonstrated acceptable agreement between the thermodilution method and echocardiographic techniques in all critically ill patients studied.

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