THE PHONOCARDIOGRAM IN IDIOPATHIC DILATATION OF THE PULMONARY ARTERY

Idiopathic dilatation of pulmonary artery: A review

The diagnosis of idiopathic dilatation of pulmonary artery is challenging because its clinical recognition is difficult and various other causes of dilated pulmonary artery need to be excluded. The clinical findings mimic various common cardiac disorders and both invasive and non-invasive investigations should be done to arrive at the diagnosis. It is a known clinical entity but etiology and pathophysiology are largely unknown. The current echocardiographic and catheterization based diagnostic criteria, may not be satisfied completely in a particular patient and need to be revisited in view of newer imaging modalities. There is paucity of information about the natural history of the disease with attendant lack of clarity in treatment guidelines. Certain cases may progress to huge dilatation and consequent serious implications. It is a rare disease and is the diagnosis of exclusion.

Utility of the physical examination in detecting pulmonary hypertension. A mixed methods study

INTRODUCTION

Patients with pulmonary hypertension (PH) often present with a variety of physical findings reflecting a volume or pressure overloaded right ventricle (RV). However, there is no consensus regarding the diagnostic utility of the physical examination in PH.

METHODS

We conducted a systematic review of publications that evaluated the clinical examination and diagnosis of PH using MEDLINE (1946-2013) and EMBASE (1947-2013). We also prospectively evaluated the diagnostic utility of the physical examination findings. Patients who underwent right cardiac catheterization for any reason were recruited. After informed consent, participants were examined by 6 physicians (3 "specialists" and 3 "generalists") who were unaware of the results of the patient's hemodynamics. Each examiner independently assessed patients for the presence of a RV lift, loud P2, jugular venous distension (JVD), tricuspid insufficiency murmur and right-sided 4th heart sound at rest and during a slow inspiration. A global rating (scale of 1-5) of the likelihood that the patient had pulmonary hypertension was provided by each examiner.

RESULTS

31 articles that assessed the physical examination in PH were included in the final analysis. There was heterogeneity amongst the studies and many did not include control data. The sign most associated with PH in the literature was a loud pulmonic component of the second heart sound (P2). In our prospective study physical examination was performed on 52 subjects (25 met criteria for PH; mPAP ≥ 25 mmHg). The physical sign with the highest likelihood ratio (LR) was a loud P2 on inspiration with a LR +ve 1.9, 95% CrI [1.2, 3.1] when data from all examiners was analyzed together. Results from the specialist examiners had higher diagnostic utility; a loud P2 on inspiration was associated with a positive LR of 3.2, 95% CrI [1.5, 6.2] and a right sided S4 on inspiration had a LR +ve 4.7, 95% CI [1.0, 15.6]. No aspect of the physical exam, could consistently rule out PH (negative LRs 0.7-1.3).

CONCLUSIONS

The presence of a loud P2 or audible right-sided 4th heart sound are associated with PH. However the physical examination is unreliable for determining the presence of PH.