From the given physical findings (the difference in BP between the radial and femoral arteries), the most probable diagnosis is coarctation of the aorta.

The classic triad of symptoms in patients with aortic stenosis is chest pain, heart failure and syncope. Pulsus parvus et tardus, pulsus alternans, hyperdynamic left ventricle, reversed splitting of the S2, prominent S4 and systolic murmur are some of the common findings of aortic stenosis. A calcified aortic valve is found in almost all adults with hemodynamically significant aortic stenosis.

CHA₂DS₂-VASc score is used for atrial fibrillation stroke risk calculation.
Congestive heart failure – 1 point
Hypertension – 1 point
Age ≥75 years – 2 points
Diabetes mellitus – 1 point
Stroke/Transient Ischemic Attack/Thromboembolic event – 2 points
Vascular disease (prior MI, PAD, or aortic plaque) – 1 point
Age 65 to 74 years – 1 point
Sex category (i.e., female sex) – 1 point
A score of 2 or more is considered as high risk and anticoagulation is indicated. This patient’s score is 3, so he needs life long warfarin to prevent stroke.

Based on the provided cardiac catheterization results, the following abnormalities are present in this patient:

1. Central Cyanosis: The presence of central cyanosis indicates decreased oxygenation of the blood. This is likely due to an intracardiac shunt, causing unoxygenated blood to mix with oxygenated blood.
2. Right-to-Left Shunt: The saturation readings in the right atrium (60%), right ventricle (55%), and pulmonary artery (55%) are all lower than the expected systemic saturation of 98%. This suggests a right-to-left shunt, allowing deoxygenated blood from the right side of the heart to enter the systemic circulation without passing through the lungs.
3. Pulmonary Hypertension: The pulmonary artery pressure of 20/5 mmHg is elevated compared to normal values, indicating pulmonary hypertension. This could be secondary to increased pulmonary blood flow or resistance, often seen in the presence of a right-to-left shunt.
4. Left-to-Right Shunt: Although not explicitly stated in the results, the elevated left atrial pressure (9 mmHg) suggests increased left-sided filling pressures. This could be due to increased blood flow from a left-to-right shunt, which commonly occurs in congenital heart defects.
5. Normal Left Ventricular Pressure: The left ventricular pressure (110/80 mmHg) falls within normal limits, indicating that the left ventricle is not significantly affected by the shunting.

Based on these findings, a likely diagnosis would be a congenital heart defect causing a right-to-left shunt, such as Tetralogy of Fallot or Eisenmenger syndrome, resulting in central cyanosis and pulmonary hypertension.

Atrioventricular septal defect (AVSD) also known as endocardial cushion defect is the most common cardiac abnormality in Down’s Syndrome.

Haemoptysis is a symptom which indicates the worsening of mitral stenosis. It occurs due to the rupture of pulmonary veins or the capillary system due to pulmonary venous hypertension. Elevated serum creatinine is seen in worsening aortic stenosis. Worsening of tricuspid regurgitation causes ascites and a pulsatile liver.

Class I indications (i.e., the benefit greatly outweighs the risk, and the treatment should be administered): -Structural heart disease, sustained VT
-Syncope of undetermined origin, inducible VT or VF at electrophysiologic study (EPS)
-Left ventricular ejection fraction (LVEF) ≤35% due to prior MI, at least 40 days post-MI, NYHA class II or III
-LVEF ≤35%, NYHA class II or III
-LVEF ≤30% due to prior MI, at least 40 days post-MI
-LVEF ≤40% due to prior MI, inducible VT or VF at EPS

Class IIa indications (i.e., the benefit outweighs the risk and it is reasonable to administer the treatment):
-Unexplained syncope, significant LV dysfunction, nonischaemic cardiomyopathy
-Sustained VT, normal or near-normal ventricular function
-Hypertrophic cardiomyopathy with 1 or more major risk factors
-Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) with 1 or more risk factors for sudden cardiac death (SCD)
-Long QT syndrome, syncope or VT while receiving beta-blockers
-Nonhospitalized patients awaiting heart transplant
-Brugada syndrome, syncope or VT
-Catecholaminergic polymorphic VT, syncope or VT while receiving beta-blockers
-Cardiac sarcoidosis, giant cell myocarditis, or Chagas disease

Indications for permanent pacemaker implantation

-Sinus node dysfunction
-Acquired Atrioventricular(AV) block (Complete third-degree AV block with or without symptoms, Symptomatic second degree AV block, Mobitz type I and II, Exercise-induced second or third degree AV block in the absence of myocardial infarction, Mobitz II with widened QRS complex)
-Chronic bifascicular block
-After acute phase of myocardial infarction
-Neurocardiogenic syncope and hypersensitive carotid sinus syndrome
-Post cardiac transplantation
-Hypertrophic cardiomyopathy
-Pacing to detect and terminate tachycardia
-Cardiac resynchronization therapy in patients with severe systolic heart failure
-Patients with congenital heart disease

Pre-eclampsia is excluded from negative proteinuria. White coat hypertension is excluded with ambulatory blood pressure monitoring. Pregnancy induced hypertension develops after 20 weeks of gestation. So the most likely answer is pre-existing hypertension. She should be investigated for a secondary cause for hypertension.

According to NICE guidelines (2013) all people who have had an acute MI, treatment should be offered with ACE inhibitor, dual antiplatelet therapy (aspirin plus a second antiplatelet agent), beta-blocker and a statin.