Makindo Medical Notes.com

Problems with prosthetic valve issues should be referred urgently to a Cardiologist

About

• These can be metal valves or bioprosthetic. Metal valves last longer but require long term anticoagulation
• Bio prosthetic valves last 10 years but do not need anticoagulation beyond the initial period
• Valve Infection is always a concern.
• All should be considered for antibiotic prophylaxis for any infective procedure according to current guidelines
• Valves can damage red cells and cause a degree of haemolysis

Mechanical Valves

• Starr Edwards: Ball/cage type. with ESM in the aortic area and opening snap if in the mitral area. low-frequency opening and closing sounds of nearly equal intensity
• Bjork-Shiley: Tilting disc with audible metallic clicks. Loud, high-frequency, metallic closing sound; soft opening sound.
• St Jude: Double tilting discs with audible metallic clicks. Loud, high-frequency, metallic closing sound; soft opening sound

Tissue Valves

• Carpentier Edwards: built on a porcine structure with 3 cusps. Needs at least 3 months of Warfarin and then this can be stopped if the patient in SR. Bioprosthetic valves offer better haemodynamics and less thrombosis like native valves. Implantation of prosthetic cardiac valves to treat haemodynamically significant aortic or mitral valve disease has become increasingly common.
• Homografts: usually from cadavers. No need to anticoagulate

Clinical

• New or worsening Heart failure: must be assumed to be due to valve malfunction until proved otherwise.
• New or worsening Murmurs: consider paraprosthetic leaks. These should be assessed with TOE |TEE
• Infection: take blood cultures must be taken for any febrile illness before giving antibiotics. Endocarditis of the prosthetic valve should be referred to a Cardiothoracic centre.
• Anti-coagulants: control is essential (INR 3.5). Always take specialist advice before any surgical intervention. Don’t stop a patient’s warfarin or reduce the dose until he/she is fully anti-coagulated with IV heparin.

Complications

• Prosthetic valve endocarditis: A history of fever or embolism should raise the possibility
• Cardio-Embolic Stroke: May be seen and as on Warfarin can have a secondary cerebral haemorrhage. Always consider endocarditis in any stroke and check CRP, fever, Echo
• Acute prosthetic valve failure: Sudden onset of dyspnoea, syncope, or precordial pain
• Acute aortic valve failure: Heart failure, Sudden death; survivors have acute severe dyspnoea, sometimes accompanied by precordial pain or syncope
• Subacute valvular failure: Symptoms of gradually worsening congestive heart failure; they also may present with unstable angina or, at times, maybe entirely asymptomatic
• Other Embolic complications: Symptoms related to the site of embolization (eg, stroke, myocardial infarction [MI], sudden death, or symptoms of visceral or peripheral embolization)
• Anticoagulant-related haemorrhage: Symptoms related to the site of haemorrhage

References

• Prosthetic Valves at Medscape