Pulmonary Artery Catheter Knotted in the Tricuspid Valve Apparatus Requiring Surgery With Cardiopulmonary Bypass: A Case Report.

Placement of a pulmonary artery catheter (PAC) is associated with complications such as entrapment or knotting. PAC entrapment in the heart, vena cava, or pulmonary artery is serious, potentially life-threatening, particularly if they are unrecognized. We present a patient with a PAC knot after aortic valve replacement. Interventional radiology (IR) determined that the catheter may have lodged in the tricuspid valve. Surgical exploration requiring cardiopulmonary bypass revealed that the PAC had passed through the tricuspid valve orifice and knotted itself around the anterior leaflet chordal structure. The catheter was unknotted, with the patient subsequently recovering without long-term sequelae.

The effect of pericardial incision on right ventricular systolic function: a prospective observational study.

BACKGROUND: Echocardiographic longitudinal markers of right ventricular (RV) systolic function are commonly depressed after coronary artery bypass graft surgery (CABG) despite an uncomplicated course and good clinical recovery. The exact timing and cause of these changes is unknown. The aim of this observational study was to monitor echocardiographic markers of RV systolic function intraoperatively during CABG. We used angle-independent speckle tracking to measure the primary endpoints of tricuspid annular plane systolic excursion (TAPSE) and tricuspid annular systolic velocity (S') before and after pericardiotomy. METHODS: Twenty-four patients undergoing elective on-pump CABG were enrolled in the study. Speckle tracking-derived TAPSE, S', free wall systolic strain, RV outflow tract strain, colour tissue Doppler-derived isovolumic acceleration (IVA) and two-dimensional RV dimensions and fractional area change (FAC) were measured at three intraoperative time points: 1) after sternotomy immediately prior to pericardiotomy; 2) after pericardiotomy and placement of pericardial retraction sutures; and 3) following cardiopulmonary bypass after chest closure. RESULTS: Adequate image quality to perform speckle tracking measurements was obtained in twenty-one patients. We found that there were no significant changes to echocardiographic parameters of RV systolic function between pre- and post-pericardiotomy. The mean (SD) of the primary endpoints were: TAPSE [28.1 (5.1) mm vs 27.7 (7.4) mm, respectively; mean difference, -0.4 mm; 97.5% confidence interval (CI), -4.0 to 3.1; P = 0.76] and S' [10.4 (2.1) cm·sec-1 vs 10.8 (1.9) cm·sec-1, respectively; mean difference, 0.4 cm·sec-1; 97.5% CI, -0.9 to 1.7; P = 0.48]. Significant reductions in the parameters of RV systolic function were found only after cardiopulmonary bypass and chest closure. CONCLUSION: Pericardial opening and suspension had no significant effect on the indices of RV systolic function derived from speckle tracking or colour tissue Doppler.

Early recovery of tricuspid annular isovolumic acceleration after mitral valve surgery - an observational study.

PURPOSE: Patients undergoing mitral valve surgery are at risk for right ventricular (RV) dysfunction resulting from increased left atrial pressure and increased pulmonary artery impedance. Measures of longitudinal measures of RV function, such as displacement, are commonly performed but have been shown to be depressed after cardiac surgery despite good patient recovery. The aim of this observational study was to assess the early perioperative time course of longitudinal transthoracic echocardiographic (TTE) markers of RV function in a patient population undergoing mitral valve surgery. METHODS: Twenty patients undergoing mitral valve surgery were enrolled in this observational study. Right ventricular longitudinal measurements (tricuspid annular plane systolic excursion [TAPSE], strain, annular velocity [S'], and isovolumic acceleration [IVA]) were performed using TTE and colour Doppler imaging preoperatively (day 1) and postoperatively (days 2 and 6). Comparisons were made between the preoperative and postoperative measurements. RESULTS: Adequate echocardiographic imaging was obtained for all 20 patients. The TAPSE, strain, and S' measures remained depressed for up to one week (i.e., day 6) after surgery compared to preoperative values. The IVA was depressed on the first postoperative day (P > 0.001), but by day 6 it was no different from the preoperative value (P = 0.37). The median [interquartile range] time to discharge from hospital was 7 [6-9] days. CONCLUSION: Persistent, significant depression of longitudinal markers of RV function despite functional improvement (discharge from hospital) make it difficult to assess recovery during the early perioperative period. Isovolumic acceleration, a load-independent measure of contractility, might be a more reliable measure of early recovery in RV function in this patient population.

Pulmonary Impedance and Pulmonary Doppler Trace in the Perioperative Period.

Pulmonary hypertension and associated vascular changes may frequently accompany left-sided heart disease in the adult cardiac surgical population. Perioperative assessment of right ventricular function using echocardiography is well established. In general, understanding the constraints upon which the right ventricle must work is mostly limited to invasive monitoring consisting of pulmonary artery pressures, cardiac output, and pulmonary vascular resistance. The latter 2 measurements assume constant (mean) flows and pressures. The systolic and diastolic pressures offer a limited understanding of the pulsatile constraints, which may become significant in disease. In normal physiology, pressure and flow waves display near-similar contours. When left atrial pressure and pulmonary vascular resistance are increased, changes in pulmonary arterial compliance will result in elevated impedance to right ventricular ejection. Pressure reflections, the result of strong reflectors, return more quickly in a noncompliant system. They augment pulmonary artery pressure causing a premature reduction in flow. As a result, pressure and flow waves will now be dissimilar. The impact of vascular changes on right ventricular ejection can be assessed using pulmonary artery Doppler spectral imaging. The normal flow velocity profile is rounded at its peak. Earlier peaks and premature reductions in flow will make it appear more triangular. In some cases, the flow pattern may appear notched. The measurement of acceleration time, the time from onset to peak flow velocity is an indicator of constraint to ejection; shortened times have been associated with increased pulmonary vascular resistance and pressure. Understanding the changes in the pulmonary arterial system in disease and the physics of the hemodynamic alterations are essential in interpreting pulmonary artery Doppler data. Analyzing pulmonary artery Doppler flow signals may assist in the evaluation of right ventricular function in patients with pulmonary vascular disease.

Pulmonary Artery Acceleration Time in Cardiac Surgical Patients.

OBJECTIVES: To examine the potential for using pulmonary Doppler to assess the hydraulic forces opposing right ventricular ejection in a perioperative setting. DESIGN: A prospective, observational study. SETTING: A university hospital tertiary-care center. PARTICIPANTS: Participants included 74 patients: 62 undergoing coronary artery bypass grafting and 12 undergoing mitral valve surgery. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: After induction of anesthesia, a pulmonary artery catheter was used to assess pulmonary artery pressures, cardiac output, and pulmonary vascular resistance. Transesophageal echocardiography was performed to measure pulsed-wave Doppler-derived acceleration time (AT) in 3 locations: the right ventricular outflow tract, the main pulmonary artery, and the right pulmonary artery. Flow reversal was observed in the main pulmonary artery in 96% of patients and possibly was responsible for the shorter ATs seen in this location. The best correlations between AT and pulmonary hemodynamic parameters were found in the right pulmonary artery. The relationships were strengthened in a subgroup of patients with elevated pulmonary capillary wedge pressure (PCWP). An acceleration time of 90 ms was associated with elevated pulmonary artery pressure and pulmonary vascular resistance. CONCLUSIONS: Flow reversal occurred frequently in the main pulmonary artery. AT in the right pulmonary artery yielded the best correlation with invasive hemodynamic parameters that were strengthened in patients with elevated PCWP. The addition of a PCWP measurement improved the reliability of AT in this patient population.

Relationship between tricuspid annular excursion and velocity in cardiac surgical patients.

OBJECTIVES: The primary objective of this study was to establish the relationship among tricuspid annular velocity (S'), tricuspid annular plane systolic excursion (TAPSE), and stroke volume (SV) in a cardiac surgical population with and without right ventricular (RV) dysfunction. The secondary objective was to assess the effect of ephedrine on these relationships in a population without RV dysfunction. DESIGN: Prospective, nonrandomized, unblinded study. SETTING: Single tertiary-level, university-affiliated hospital. PARTICIPANTS: Twenty-seven patients undergoing elective coronary artery bypass grafting with no evidence of RV dysfunction (Group 1). Sixteen ventilated postcardiac surgical patients with suspected RV dysfunction (Group 2). INTERVENTIONS: Ten mg of intravenous ephedrine to Group 1 only. MEASUREMENTS AND MAIN RESULTS: Using transthoracic echocardiography, S' and TAPSE were measured using color tissue Doppler applied at the RV base in a 4-chamber view. SV was calculated using thermodilution. Six patients in Group 1 and 6 patients in Group 2 were excluded because of poor imaging or ineligibility. Modest correlation was found between TAPSE and SV in Group 1 (R = 0.50, p<0.001). There was no correlation between TAPSE and SV in Group 2. There was no correlation between S' and SV in both groups. In Group 1, the relationship between TAPSE and S' was curvilinear (R = 0.74 pre-ephedrine, p<0.001; R = 0.64, p = 0.009 post-ephedrine). There was no relationship between TAPSE and S' in Group 2. Ephedrine increased S' and TAPSE. The TAPSE-S' relationship was not significantly altered. CONCLUSIONS: In the presence of RV dysfunction, TAPSE did not correlate with cardiac output. In the absence of RV dysfunction, the relationship between TAPSE and S' described a curvilinear relationship.

Flow velocity patterns in the pulmonary artery and pulmonary hypertension.

Pulmonary hypertension impacts negatively on right ventricular function; however, understanding pulmonary vasculature can be difficult. Data from invasive monitoring or traditional echocardiography may not represent the full extent of pulmonary arterial disease. An important element missing from invasive monitoring is the ability to take into account the effects of pulsatile flow; therefore, mean pressures and mean flows are employed in the calculation of pulmonary vascular resistance. Traditional echocardiography yields right ventricular systolic pressures but only in the presence of tricuspid regurgitation. In these Perioperative Cardiovascular Rounds, we show the utility of interpreting pulmonary artery (PA) pulsed-wave Doppler (PWD) and colour-flow Doppler in the assessment of the pulmonary vasculature, and we describe the physiology behind their genesis. We show these concepts in a case vignette involving a patient in a low cardiac output state after a complex re-do sternotomy. Additionally, we describe four distinct patterns of PA PWD tracings and illustrate the ability of PA PWD analysis to assess the pulmonary vasculature in both a qualitative and semi-quantitative way. In the critical care setting, it is vital to understand alterations in the pulmonary circulation, and analysis of PA PWD can provide additional information to complement data from other sources.

Evaluation of TAPSE as a measure of right ventricular output.

PURPOSE: This study was designed to show the relationship between tricuspid annular plane systolic excursion (TAPSE) and stroke volume (SV) by thermodilution using three different methods and also to assess whether TAPSE can track hemodynamic changes associated with volume loading and ephedrine administration. METHODS: This was an observational study in 61 elective patients with a pulmonary artery catheter who were undergoing coronary artery bypass graft surgery in a cardiac surgical centre. We measured TAPSE by three methods using transesophageal echocardiography: M mode, speckle tracking at the lateral wall, and tissue tracking at the inferior wall. There were two interventions: leg raising (volume recruitment) or administration of ephedrine 5 mg iv. Echo and hemodynamic measurements were performed before and after each intervention. RESULTS: Eleven patients were excluded due to poor imaging. There were 26 patients in the leg raising group and 24 patients in the ephedrine group. The correlation coefficient between stroke volume (SV) and TAPSE by M mode, speckle tracking, and tissue tracking was 0.48, 0.44, and 0.09, respectively. There was a significant increase in SV following each intervention; however, the changes in TAPSE by any method and velocity were not large enough to reach statistical significance. CONCLUSION: Tricuspid annular plane systolic excursion by M mode and by speckle tracking correlates modestly with SV. There was no correlation between TAPSE and SV by tissue tracking at the inferior wall of the right ventricle. Tricuspid annular plane systolic excursion by M mode and by speckle tracking does not track changes in SV following either volume loading or ephedrine administration.

Speckle tracking for the intraoperative assessment of right ventricular function: a feasibility study.

OBJECTIVES: Speckle tracking is an ultrasound method that assesses B-mode features to measure tissue displacement and derive deformation parameters. The objective of this study was to assess the feasibility of using speckle tracking in the measurement of right ventricular (RV) longitudinal strain during cardiac surgery using transesophageal echocardiography (TEE). DESIGN: This was a prospective, observational cohort study. SETTING: A single university hospital setting. PARTICIPANTS: Twenty-one patients without valvular disease referred for coronary artery bypass graft surgery were studied. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: After the induction of anesthesia and mechanical ventilation, transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) were used to obtain tricuspid annular plane systolic excursion (TAPSE), RV fractional area of change (FAC), and 2-dimensional strain analysis (speckle tracking) on 3 consecutive heart beats. There was a larger percentage of measurable segments achieved when using TEE. All segments could be analyzed per cardiac cycle in 73% of loops when using TEE and 38% when using TTE. The global strain value was similar using both methods (TEE: -20.4%, TTE: -20.1%). The TAPSE could be measured in only 52% of the segments using TTE and 100% using TEE. The FAC could be measured in 90.5% of the loops using TEE and in only 33.3% of the loops using TTE. CONCLUSIONS: Perioperative measurements of RV strain using TEE in ventilated patients is feasible. The success rate was higher using TEE in ventilated patients under anesthesia. Differences between the 2 methods were likely the result of differences in 2-dimensional image quality.

Induction of anesthesia does not alter tricuspid annular velocities: a tissue Doppler assessment.

PURPOSE: In this prospective observational cohort study, we investigated whether tricuspid annular velocities (TAV) are altered after induction of anesthesia in patients undergoing coronary artery bypass graft (CABG) surgery. METHODS: Twenty-four elective CABG patients were assessed before and after induction of anesthesia, and a convenience sample of nine healthy volunteers was used for comparison of TAV only. Measurements included mean arterial pressure (MAP), heart rate (HR), pulmonary artery pressure (PAP), and cardiac index (CI) as assessed post-induction. Tricuspid annular plane systolic excursion (TAPSE) was measured in anatomical M-mode. The S (systolic) wave velocity and isovolemic acceleration (IVA) were measured from colour tissue Doppler (TD). Paired and unpaired Student's t tests were used to compare all variables pre-and post-induction. RESULTS: In response to anesthetic induction, MAP decreased from 105 +/- 14 to 79 +/- 9 mmHg, but HR was unchanged (67 +/- 13 beats x min(-1) pre-induction compared with 67 +/- 9 beats x min(-1) post-induction). The mean PAP and CI post-induction were 20 +/- 6 mmHg and 2.3 +/- 0.4 L x min(-1) x m(-2), respectively. While there was no change post-induction in either S velocity (8.80 +/- 1.23 vs 9.0 +/- 1.92 cm x sec(-1)) or IVA (1.63 +/- 0.61 vs 1.84 +/- 0.83 m x sec(-2)), TAPSE decreased from 23 +/- 4 to 21 +/- 4 mm (P = 0.039). All pre-induction echocardiographic variables were lower in the CABG group compared with the normal group (IVA: 2.34 +/- 0.34 m x sec(-2), S wave: 11.14 +/- 2.78 cm x sec(-1), TAPSE 2D: 26 +/- 4 mm), respectively. CONCLUSIONS: Induction of anesthesia for CABG surgery does not alter velocity-based parameters of RV function. There was a small decrease in TAPSE. The TD parameters were lower in CABG patients compared with the normal group.

The right ventricle in cardiac surgery, a perioperative perspective: I. Anatomy, physiology, and assessment.

The importance of right ventricular (RV) function in cardiovascular disease and cardiac surgery has been recognized for several years. RV dysfunction has been shown to be a significant prognostic factor in heart failure, congenital heart disease, valvular disease, and cardiac surgery. In the first of our two articles, we will review key features of RV anatomy, physiology, and assessment. In the first article, the main discussion will be centered on the echographic assessment of RV structure and function. In the second review article, pathophysiology, clinical importance, and management of RV failure in cardiac surgery will be discussed.

The right ventricle in cardiac surgery, a perioperative perspective: II. Pathophysiology, clinical importance, and management.

The importance of right ventricular (RV) function in cardiovascular disease and cardiac surgery has been recognized for several years. RV dysfunction has been shown to be a significant prognostic factor in cardiac surgery and heart transplantation. In the first article of this review, key features of RV anatomy, physiology, and assessment were presented. In this second part, we review the pathophysiology, clinical importance, and management of RV failure in cardiac surgery.

The effect of heart rate on tricuspid annular velocities in cardiac surgical patients with atrial fibrillation.

OBJECTIVES: Tricuspid annular isovolumic acceleration is a load-independent measure of contractility, but its relationship to heart rate is unknown in humans. The authors investigated the effect of heart rate on measurements of isovolumic acceleration and systolic wave velocities in postoperative cardiac surgical patients with atrial fibrillation. DESIGN: This was a prospective observational study. SETTING: Single-university hospital setting. PARTICIPANTS: Postoperative cardiac surgical patients with atrial fibrillation. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Lateral tricuspid isovolumic acceleration and peak systolic wave velocity were measured using color-tissue Doppler. The corresponding heart rate was calculated from the preceding R-R interval. Regression analysis was used to assess the relationship between heart rate and tricuspid annular velocity. A heart rate threshold value was determined at which the tissue Doppler variables were significantly altered by heart rate. Seven hundred fifteen beats in 15 patients were analyzed. There was a positive linear correlation between isovolumic acceleration and heart rate and a negative polynomial correlation between the systolic wave and heart rate. A significant reduction in systolic wave velocity occurred at heart rates greater than 110 beats/min. CONCLUSIONS: In this patient population, isovolumic acceleration significantly increased with increasing heart rate. Tachycardia-induced preload alterations and impaired force-frequency responses may have been responsible for the decrease in systolic wave velocities.

Regional differences in color tissue Doppler-derived measures of longitudinal right ventricular function using transesophageal and transthoracic echocardiography.

OBJECTIVE: This study was designed to compare the right ventricular (RV) Doppler tissue imaging parameters of tricuspid annular isovolumic acceleration (IVA), systolic velocity (S), and basilar myocardial strain and strain rate (SR) by using both transesophageal echocardiography (TEE) (inferior wall) and transthoracic echocardiography (TTE) (free wall) in a cardiac surgical population under general anesthesia. DESIGN: Prospective observational study. SETTING: University hospital. PARTICIPANTS: Twenty-four elective patients undergoing coronary artery bypass surgery. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Under general anesthesia, simultaneous Doppler tissue-imaging measurements of tricuspid annular velocities and basilar myocardial deformation were performed by using both TEE and TTE approaches. Interclass correlation coefficients were used to compare the measurements using both methods. When TEE and TTE methods were compared, there was good correlation for the IVA (r = 0.70) but no correlation for S-wave velocities, strain, and SR. The S-wave velocities were lower using the TEE approach. The basilar strain and SR were higher using the TEE approach. CONCLUSIONS: In cardiac surgical patients under anesthesia, the IVA appears to be the most consistent variable in the evaluation of RV function measured by either the TTE (lateral wall) or TEE (inferior wall). Technical difficulties may preclude the use of the deformation parameters in the assessment of RV function.