Familial amyloid cardiomyopathy
Description
● Background:
Transthyretin protein buildup in the myocardium results in increased wall thickness and diastolic dysfunction, which causes transthyretin amyloid cardiomyopathy (ATTR-CM), an infiltrative progressive heart disease.
● Two types:
Hereditary (ATTRm): caused by a mutation in the gene that produces an unstable TTR protein.
Wild type (ATTRwt) – age-related.
More prevalent in African-Americans (3–4%), men, and the elderly.
Lately diagnosed and frequently underdiagnosed.
Particularly in uncommon or early cases, early suspicion is crucial.
● Case Presentation:
The patient is a 62-year-old male African American who has ran in the Olympics.
➣Past history:
Past medical history includes bilateral carpal tunnel surgery, hypertension, prostate cancer, and hyperlipidaemia.
➣Early signs (age 55):
Atrial flutter, Mobitz II AV block, which was ablationed, and a pacemaker at age 58 were the initial symptoms (at age 55).
Later symptoms include orthopnea, leg oedema, and dyspnoea while exerting oneself.
➣Echocardiogram:
bi-atrial enlargement, LVEF 50%, LV thickness, and strain imaging revealed apical/septal sparing (red flag).
➣ECG: sinus rhythm, no left ventricular enlargement.
Restrictive cardiomyopathy is suspected.
Pathogenic mutation of the transthyretin gene (V122I) is a genetic test.
An ambiguous technetium-pyrophosphate scan indicates amyloidosis.
➣Exclusion: AL amyloidosis was ruled out due to serum/urine protein electrophoresis showing no monoclonal proteins.
Pressures associated with restricted physiology during right heart catheterisation.
➣After an endomyocardial biopsy, amyloid deposition was verified by Congo red stain → green birefringence.
➣Transthyretin amyloid was verified by mass spectrometry.
Medical treatment for heart failure and tafamidis is the planned course of treatment.
● Discussion:
ATTR-CM prevalence is rising due to better screening, but still underdiagnosed.
➣Highest mortality: black men; regional disparities linked to healthcare access and specialized centers.
➣Early recognition is crucial – red flags:
Bilateral carpal tunnel syndrome,
Unexplained arrhythmias or conduction disease,
➣Need for pacemaker at young age,
➣Diastolic heart failure not explained by hypertension or hypertrophic cardiomyopathy.
➣Clinical presentation can vary (cardiac vs neurologic).
➣Genetic screening should be considered in suspected cases, even at <65 years.
➣Multidisciplinary teams and referral centers improve diagnosis and management.
Protocol
● Congestion / Fluid Overload (edema, dyspnea,
➣Medical management: for congestion and fluid overload (oedema, dyspnoea, orthopnea) includes diuretics, a low-salt diet, and fluid restriction.
➣Interventions in Nursing:
• Track daily weight, intake, output, and oedema scores.
• Verify oxygen saturation and breath sounds.
• To facilitate breathing, place the patient in semi-Fowler's.
• Spread knowledge about fluid restriction and reduced sodium consumption.
• Keep an eye out for electrolyte imbalance and diuretic-induced hypotension.
● Decreased Cardiac Output/ Fatigue:
➣Medical Management: Energy-saving techniques and standard heart failure therapy.
➣Interventions in Nursing:
• Track perfusion, including skin tone, heart rate, and urine production.
• Promote relaxation and help with everyday tasks.
• Prevent sluggish position shifts, or orthostatic hypotension.
• Serve modest, regular meals that are heavy in protein.
• Encourage mild exercise and activities as tolerated.
● Arrhythmias and Issues with Conduction:
➣Medical Management: Medication as required, pacemaker already in place.
➣Nursing Interventions:
• Arrhythmia telemetry monitoring.
• Check for dizziness, syncope, and palpitations.
• Monitor pacemaker performance and report any irregularities.
•Teach the patient to promptly report any new arrhythmia symptoms.
● Multiple diagnostic procedures are required:
➣Medical Management: Genetic screening, biopsy, and right heart catheterisation
➣Nursing Interventions:
• Prior to the surgery, get the patient mentally and physically ready.
• After the procedure, keep an eye on vital signs, bleeding, and arrhythmias.
• Maintain a clean biopsy access site and keep an eye out for infections.
• Offer comfort and give straightforward explanations of processes.
● Psychological Stress (detection of uncommon diseases)
➣Medical Management: Family engagement and counselling.
➣Nursing interventions include:
•Active listening and emotional support.
•Involve family members in conversations about care.
•Make use of patient support groups and genetic counselling.
•Keep an eye out for signs of sadness or anxiety and seek mental health help if necessary.
● Adherence to medication and adverse effects
➣Medical Management: Tafamidis, a disease-modifying medication, was started.
➣Interventions by Nurses:
• Provide information about the dosage, timing, and potential adverse effects of tafamidis.
• Use alarms and pill boxes as reminders to ensure adherence.
• Track GI tolerance and liver function.
• Inspire people to report any new or worsening symptoms.
● Nutritional Difficulties and Cachexia Risk
➣Medical Management: Supplements if necessary, dietitian support.
➣Nursing Interventions:
• Evaluate nutritional labs, weight, and BMI.
• Promote a diet rich in protein and nutrients.
•GI symptoms, such as nausea and early satiety, should be managed.
• Work with a dietician to create a customised plan.
● Monitoring the Progression of Disease
➣Medical Management: Biomarkers (NT-proBNP), routine imaging (echo, PYP scan).
➣Interventions by Nurses:
• Monitor symptom changes (oedema, tolerance to exercise).
•Note and report indications of improvement.
• Arrange follow-ups and make sure appointments are kept.
● Multidisciplinary Care Coordination
➣medical management: Experts in cardiology, genetics, and amyloidosis are involved.
➣Nursing interventions:
• Serve as a liaison between patients, families, and experts.
• Clear follow-up instructions and discharge planning should be provided.
• Inform the patient about warning signs (sudden fainting, increasing oedema).
• Assist in setting up family members' genetic testing.
Notes
For more information visit
10.1177/21501319211062682
