The goal of this observational study is to assess the efficacy that the addition of novel markers cardiac function, particularly of right ventricular (RV) function in echocardiography, and ECG have in detecting pulmonary hypertension.

The main questions it aims to answer are:

Can novel markers in ECG and echocardiography suggest the presence of PH? Can existing screening guidelines be improved with the addition of these markers?

Pulmonary Hypertension (PH) is a condition caused by high blood pressure in the blood vessels that carry blood to the lungs. It can cause severe breathlessness and failure of the right side of the heart. Sadly it is often fatal.

PH can be caused by a number of different conditions and life expectancy varies with the underlying cause, ranging from months to years. For some subtypes of PH, effective treatments exist which can significantly improve life expectancy and quality of life. Accurate tools for the assessment of PH are therefore essential, so that we can better understand and predict life expectancy and so that life-saving medications can be started earlier.

Once doctors suspect that somebody has PH, they refer them to a specialist PH centre for assessment and a procedure called right heart catheterisation (RHC), which will confirm the diagnosis. However, evidence for the suspicion of PH is frequently overlooked, leading to an average delay to diagnosis from onset of symptoms of two years. This late presentation negatively impacts survival for these patients and prevents them promptly starting the effective treatments which are available.

An electrocardiogram (ECG) is a recording of the heart's electrical signals, printed in waveforms. It is a painless, low-cost, and readily-available test used in PH assessment.

Echocardiography (echo) is a quick, safe and well-tolerated test often requested to investigate breathless patients and can provide useful information about the suspicion of PH. Echo has however been shown to lack accuracy in milder forms of the disease. It has been hypothesised that subtle markers of right ventricular function by echo, such as free wall strain (RVFWS) begin to deteriorate before the more established findings.

A large, cross-population study of ECG features and echo markers such as RVFWS both in isolation and in combination, in patients referred for PH assessment may help identify these markers, and improve detection of the disease.

Inclusion Criteria:

• Patients 18+ who have undergone TTE, ECG and RHC as part of their clinical care

Exclusion Criteria:

• Patients <18 years old
• Known or suspected congenital heart disease
• Patient has opted-out of allowing their data to be used for research and planning (via the national data opt-out choice in England, or equivalent data protection scheme in Scotland)

Patients aged 18+ referred for first time assessment of PH, who have undergone ECG, TTE, and RHC as part of their routine investigation.