Pulmonary hypertension: An update of Dx and Tx guidelines

Radiographic findings that suggest PH include enlargement of central pulmonary arteries and the right ventricle and dilation of the right atrium. Pulmonary vascular congestion might also be seen, secondary to left heart disease.⁷

Electrocardiographic findings of PH are demonstrated by signs of left ventricular hypertrophy, especially in Group 2 PH. Upright R waves in V₁-V₂ with deeper S waves in V₅-V₆ might represent right ventricular hypertrophy or right heart strain. Frequent premature atrial contractions and multifocal atrial tachycardia are also associated with PH.⁷

Brain natriuretic peptide (BNP) or N-terminal (NT) proBNP. The level of BNP might be elevated in PH, but its role in the diagnostic process has not been established. BNP can, however, be used to monitor treatment effectiveness and prognosis.¹⁵ A normal electrocardiogram in tandem with a normal level of BNP or NT-proBNP is associated with a low likelihood of PH.⁶

Transthoracic echocardiography (TTE) is the initial evaluation tool whenever PH is suspected. Echocardiographic findings suggestive of PH include a combination of ­tricuspid regurgitation velocity > 2.8 m/s ­(FIGURE 2); estimated pulmonary artery systolic pressure > 35 mm Hg in younger adults and > 40 mm Hg in older adults; right ventricular hypertrophy or strain; or a combination of these. Other TTE findings suggestive of PH are related to the ventricles, pulmonary artery, inferior vena cava, and right atrium (TABLE 2⁶). The probability of PH based on TTE findings is categorized as low, intermediate, or high (see TABLE 2⁶ and TABLE 3¹⁶ for details).

Older guidelines, still used by some, rely on the estimated pulmonary artery systolic pressure (ePASP) reading on echocardiography.^13,17 However, studies have reported poor correlation between ePASP readings and values obtained from RHC.¹⁸

TTE also provides findings of left heart disease, such as left ventricular systolic and diastolic dysfunction and left-sided valvular pathology. Patients with suspected PH in whom evidence of left heart disease on TTE is insufficient for making the diagnosis should receive further evaluation for their possible status in Groups 3-5 PH.

Ventilation–perfusion (VQ) scan. If CTEPH is suspected, a VQ scan should be performed. The scan is highly sensitive for CTEPH; a normal VQ scan excludes CTEPH. Computed tomography (CT) of the chest is not helpful for identifying chronic thromboembolism.¹³

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