Figures
- FIGURE 1
Diagnostic algorithm for pulmonary arterial hypertension (PAH). PH: pulmonary hypertension; PFT: pulmonary function testing; BGA: blood gas analysis; HRCT: high-resolution computed tomography; RV: right ventricular; V′/Q′: ventilation/perfusion; CTEPH: chronic thromboembolic pulmonary hypertension; CT: computed tomography; RHC: right heart catheterisation; PEA: pulmonary endarterectomy; mPAP: mean pulmonary arterial pressure; PAWP: pulmonary arterial wedge pressure; PVR: pulmonary vascular resistance; CTD: connective tissue disease; PVOD: pulmonary veno-occlusive disease; PCH: pulmonary capillary haemangiomatosis; CHD: congenital heart disease. Reproduced and modified from [4] with permission from the publisher.
- FIGURE 2
Best practice recommendations for right heart catheterisation: pressure transducer and zeroing [3, 20]. The joint task force of the European Society of Cardiology and the European Respiratory Society recommends setting the pressure transducer to zero at the mid-thoracic line (with a suggested reference point defined by the intersection of the frontal plane at the mid-thoracic level, the transverse plane at the level of fourth anterior intercostal space, and the midsagittal plane [20]) in a supine patient halfway between the anterior sternum and the bed surface [4]. Reproduced from [20] with permission from the publisher.
- FIGURE 3
Representative pressure tracings of a) pulmonary arterial pressure and b) pulmonary arterial wedge pressure (PAWP). Both recordings display respiratory variations, and the correct measurements should be made at the end of the expiratory phase (arrows). For measurement of PAWP (b), the digital read is usually obtained automatically and averages over the inspiration and expiration, with a resultant value of 4 mmHg. The correct value is indicated by the arrow marking the end-expiratory phase when the respiratory system is at functional residual capacity and is 10 mmHg.
- FIGURE 4
Potential for misclassification of pulmonary hypertension with reliance on end-expiratory pulmonary arterial wedge pressure (PAWP). Distribution of PAWP at end exhalation versus as calculated by the respiratory mean according to clinical phenotype. Larger circles represent identical observations in multiple patients. Blue circles above 15 mmHg represent phenotypically pre-capillary patients who would have been misclassified as having pulmonary venous hypertension using end-expiratory PAWP. Reproduced from [30] with permission from the publisher.
Tables
- TABLE 1
Practical recommendations relating to parameters measured or derived from right heart catheterisation
Haemodynamic variable Method of measurement Range in healthy subjects# Range in PAH Practical recommendation¶ Cardiac output L·min−1 Measure pulmonary blood flow:
1) Using the indicator dilution principle (thermodilution) or
2) Based on oxygen consumption (Fick method) Oxygen consumption can be obtained from blood gas analysis or pulse oximetry4–6 Normal or decreased The preferred method is thermodilution, although the indirect Fick technique is acceptable Perform oximetry in patients with a pulmonary artery oxygen saturation >75% and in the event of suspected cardiac left-to-right shunt Cardiac index L·min−1·m−2 Calculated using: Cardiac index=cardiac output/BSA 2.4–4 Normal or decreased PAWP mmHg Tracings to measure pressure waveforms 4–12 ≤15 Inflate the balloon in the right atrium and advance the catheter until it reaches the PAWP position Avoid repeated inflations and deflations of the balloon (and removal when inflated) to minimise risk of pulmonary artery rupture Record PAWP as the mean of three end-expiratory measurements mPAP mmHg Calculated using: mPAP=diastolic PAP+ (systolic–diastolic PAP)/3 Systolic: 15–25 Diastolic: 4–12 mPAP: 14±3 mPAP: ≥25 PVR Wood units and PVRI Wood units·m−2 Calculated using: PVR=(mPAP–mean PAWP)/cardiac output PVRI=PVR/BSA ≤3 PVR: >3 PVRI: ≥6 For harmonisation, PVR should be expressed in Wood units It may also be expressed as dyn·s−1·cm−5 (conversion: Wood units×80) RAP mmHg Tracings to measure pressure waveforms 1–6 Normal or elevated RVP mmHg Tracings to measure pressure waveforms Systolic: 15–25 Diastolic 1–8 >30 Normal, or elevated SVR Wood units Calculated using: SVR=(mSAP–RAP)/cardiac output 8.8–20 PVR/SVR: <0.75 In general, a ratio of PVR to SVR >0.75 indicates significant pulmonary vascular disease TPG mmHg Calculated using: TPG=mPAP–PAWP ≤12 >12 May be used to determine a pre-capillary component in post-capillary PH DPG mmHg Calculated using: DPG=diastolic PAP–PAWP <6 >3 May be used to determine a pre-capillary component in post-capillary PH PAH: pulmonary arterial hypertension; PAWP: pulmonary arterial wedge pressure; PAP: pulmonary arterial pressure; PVR: pulmonary vascular resistance; PVRI: pulmonary vascular resistance index; RAP: right atrial pressure; RVP: right ventricular pressure; SVR: systemic vascular resistance; TPG: transpulmonary pressure gradient; DPG: diastolic pressure gradient; BSA: body surface area; mPAP: mean pulmonary arterial pressure; mSAP: mean systemic arterial pressure; PH: pulmonary hypertension. #: values for PVR and PAP have been identified in additional studies of healthy subjects [18, 19]; ¶: information for practical recommendations from [3, 15, 17]. Information from [3, 11–19].
- TABLE 2
Contraindications and complications associated with right heart catheterisation
Contraindications [36–38] Absolute: mechanical tricuspid or pulmonic valve, right heart masses (thrombus or tumour), and right-sided endocarditis Relative: coagulopathy, pacemaker, bioprosthetic tricuspid or pulmonic valve, left bundle branch block, arrhythmias, and skin site infections Complications# [34] Haematoma at puncture sites, pneumothoraces, arrhythmias, vasovagal episodes, hypotensive episodes, and pulmonary haemorrhage #: the complications listed are those that occur most frequently.
Disclosures
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