Predictive value of prominent right atrial V waves in assessing the presence and severity of tricuspid regurgitation

Tricuspid regurgitation in patients with pacemakers and implantable cardiac defibrillators: a comprehensive review

Implantable cardiac devices, including defibrillators and pacemakers, may be the cause of tricuspid regurgitation (TR) or may worsen existing TR. This review of the literature suggests that TR usually occurs over time after lead implantation. Diagnosis by clinical exam and 2-dimensional echocardiography may be augmented by 3-dimensional echocardiography and/or computed tomography. The mechanism may be mechanical perforation or laceration of leaflets, scarring and restriction of leaflets, or asynchronized activation of the right ventricle. Pacemaker-related TR might cause severe right-sided heart failure, but data regarding associated mortality are lacking. This comprehensive review summarizes the data regarding incidence, mechanism, and treatment of lead-related TR.

Cardiac Output Measured by a New Arterial Pressure Waveform Analysis Method Without Calibration Compared With Thermodilution After Cardiac Surgery

OBJECTIVES

To investigate whether measuring cardiac output and its course after cardiac surgery by a new analysis technique of radial artery pressure waves, without need for calibration (FloTrac/Vigileo [FV]; Edwards Lifesciences, Irvine, CA), conforms to the standard bolus thermodilution method via a pulmonary artery catheter (PAC).

DESIGN

Prospective study.

SETTING

Intensive care unit of university hospital.

PARTICIPANTS

Twenty patients for up to 24 hours after cardiac surgery.

INTERVENTIONS

Simultaneous and triplicate PAC thermodilution and FV cardiac output measurements at 1 and 3 hours after surgery and the following morning.

MEASUREMENTS AND MAIN RESULTS

Fifty-six simultaneous measurement sets were obtained. Mean cardiac output (PAC) ranged between 2.8 and 10.3 L/min and for the FV method between 3.3 and 8.8 L/min. The coefficient of variation for pooled measurements was 7.3% for the PAC and 3.0% for the FV method. For pooled data, the r2 was 0.55 (p < 0.001), with a bias of -0.14, precision of 1.00 L/min, and 95% limits of agreement between -2.14 and 1.87 L/min in a Bland-Altman plot. Also, the FV method tended to overestimate cardiac output when <7 L/min and increased with time, whereas mean arterial pressure increased and PAC cardiac output did not change. Changes in cardiac output correlated (r2 = 0.52, p < 0.001).

CONCLUSIONS

The FV arterial pressure waveform analysis method is a clinically applicable method for cardiac output assessment without calibration, after cardiac surgery. It performs well at low cardiac outputs but remains sensitive to changes in vascular tone.

The hemodynamic signs of constrictive pericarditis can be mimicked by tricuspid regurgitation

A case with clinical and hemodynamic findings consistent with constrictive pericarditis is reported. At surgery, the pericardium was not thickened or adherent to the epicardial wall. As suggested by echocardiography, a diagnosis of severe tricuspid regurgitation was confirmed. This case illustrates that invasive hemodynamic findings consistent with a picture of pericardial constriction can be produced by processes other than constrictive pericarditis.

Right ventricular response to high-dose almitrine infusion in patients with severe hypoxemia related to acute respiratory distress syndrome

OBJECTIVE

To evaluate the effects of high-dose almitrine infusion on gas exchange and right ventricular function in patients with severe hypoxemia related to acute respiratory distress syndrome (ARDS).

DESIGN

Prospective study.

SETTING

Medicosurgical intensive care department (ten beds).

PATIENTS

Nine patients with ARDS and severe hypoxemia (PaO2/FIO2 ratio, <150 torr [20 kPa]).

INTERVENTION

High-dose almitrine infusion (16 microg/kg/min for 30 mins).

MEASUREMENTS AND MAIN RESULTS

Gas exchange and hemodynamic parameters were recorded before and after almitrine infusion. Right ventricular function was evaluated by using a fast response thermistor pulmonary artery catheter that allowed measurement of right ventricular ejection fraction and calculation of right ventricular end-diastolic and end-systolic volumes. Almitrine did not significantly alter arterial oxygenation and intrapulmonary shunt. Almitrine increased mean pulmonary arterial pressure (MPAP) from 31 +/- 4 to 33 +/- 4 mm Hg (p < .05), pulmonary vascular resistance index from 353 +/- 63 to 397 +/- 100 dyne x sec/ cm5 x m2 (p < .05), and right ventricular end-systolic volume index from 71 +/- 22 to 77 +/- 21 mL/m2 (p < .05); almitrine decreased right ventricular ejection fraction from 36% +/- 7% to 34% +/- 8% (p < .05). Stroke volume index and cardiac index did not change. The almitrine-induced changes in right ventricular ejection fraction were closely correlated with the baseline MPAP (r2 = .71, p < .01).

CONCLUSION

In patients with severe hypoxemia related to ARDS, high-dose almitrine infusion did not improve arterial oxygenation and impaired the loading conditions of the right ventricle. The decrease in right ventricular ejection fraction induced by almitrine was correlated with the baseline MPAP. Thus, high-dose almitrine infusion may be harmful in ARDS patients with severe hypoxemia and pulmonary hypertension.