Functional mitral regurgitation (FMR) and tricuspid regurgitation (FTR) occur due to cardiac remodeling in the presence of structurally normal valve apparatus. Two main mechanisms are involved, distinguishing an atrial functional form (when annulus dilatation is predominant) and a ventricular form (when ventricular remodeling and dysfunction predominate). Both affect the prognosis of patients with heart failure (HF) across the entire spectrum of left ventricle ejection fraction (LVEF), including preserved (HFpEF), mildly reduced (HFmrEF), or reduced (HFrEF). Currently, data on the management of functional valve regurgitation in the various HF phenotypes are limited. This review summarizes the epidemiology, pathophysiology, and treatment of FMR and FTR within the different patterns of HF, as defined by LVEF.

Cardiac amyloidosis (CA) manifests as infiltrative cardiomyopathy with a hypertrophic pattern, usually presenting with heart failure with a preserved ejection fraction. In addition, degenerative valvular heart disease, particularly severe aortic stenosis, is commonly seen in patients with CA. However, amyloid fibril deposition might also infiltrate the conduction system and promote the development of electrical disorders, including ventricular tachyarrhythmias, atrio-ventricular block or acute electromechanical dissociation. These manifestations can increase the risk of sudden cardiac death. This review summarises the pathophysiological mechanisms and risk factors for sudden cardiac death in CA and focuses on the major current concerns regarding medical and device management in this challenging scenario.

A carcinoid tumore is a rare neuroendocrinologic malignancy that commonly origins from enterochromaffin or Kulchitsky cells in the gastrointestinal tract and secretes bioactive molecules in blood. Up to 60% of patients with carcinoid tumors have cardiac involvement, often on the right-sided heart valves (typically the tricuspid valve and the pulmonic valve). A 66 year old woman was admitted to hospital with congestive heart failure, chronic diarrhea and weight loss. A contrast-enhanced computed tomography scan of the liver showed multiple masses (the largest 70 mm×45mm) compatible with metastases. A transthoracic echocardiogram showed dilatation of right sections of the heart with severe tricuspid regurgitation (RV 64 ml/beat, ERO 1 cmq) and mild pulmonary valve stenosis (Peak gradient 13 mmHg). Patient's aortic and mitral valves were normal in structure and function. The EKG revealed low-voltage QRS complexes of all leads, unspecific ST segment changes and sinusal rhythm. The blood tests showed a significant increase in chromogranin A (17670 ng/ml) and enolase; a 24-hour urine collection showed a total output of 5-hydroxyindoleacetic acid eleveted. A biopsy of the liver with immunostaining for chromogranin and synaptophysin were strongly positive and confirmed the diagnosis of metastatic carcinoid syndrome (grade 1, cells CDX2 positive). The echocardiographic findings of carcinoid heart disease is drumstick-like, rigid, and shortened leaflets with a visible regurgitant orifice, causing torrential tricuspid regurgitation. The pulmonic valve presents more frequently valvular stenosis. A combination of biomarkers and cardiac imaging is useful in screening and diagnosis of carcinoid heart involvement in patients with carcinoid syndrome. The management of carcinoid heart disease is hardful and requires a multidisciplinary approach, medical and surgical treatment, for optimized care.

Cardiac amyloidosis (CA) manifests as infiltrative cardiomyopathy with a hypertrophic pattern, usually presenting with heart failure with preserved ejection fraction (HFpEF). In addition, degenerative valvular heart disease, particularly severe aortic stenosis, is commonly seen in patients with CA. However, amyloid fibril deposition may also infiltrate the conduction system and promote the development of electrical disorders, including ventricular tachyarrhythmias (VT), atrio-ventricular block, or acute electromechanical dissociation (EMD). These manifestations can increase the risk of sudden cardiac death (SCD). This review summarizes the pathophysiological mechanisms and risk factors for sudden cardiac death in cardiac amyloidosis and focuses on the major current concerns regarding medical and device management in this challenging scenario. Heart involvement is the major determinant of survival in patient with amyloidosis and a “sudden death” occurs in approximately two-thirds of patients with cardiac amyloidosis. Moreover, the AL amyloid fibrils are shown to be highly cytotoxic to the ventricular myocardial, explaining why ventricular arrhythmias appear more frequently in AL over ATTR. Proposed mechanisms driving electrophysiological manifestations of CA involve intramural coronaries, microvascular ischemia, or patchy myocardium infiltration of amyloid fibrils, causing the development of anatomical re-entrant circuits responsible for ventricular arrhythmia. The prevalence of non-sustained ventricular tachycardia (NSVT) in AL amyloidosis ranges from 5 to 27% with routine monitoring and 100% during the stem cell transplant period. The guidelines don't provide specific indications regarding insertion of implantabile cardioverter defibrillator (ICD) and they don't clarify whether some patients subtypes can benefit from them. Amyloid infiltration into the conduction system enhances the genesis of rhythm disturbances, including fatal ventricular arrhythmias and SCD. Current pharmacological anti-arrhythmic therapies are poorly tolerated in CA, and there are no robust recommendations on the management of ventricular arrhythmias in this subset of patients. Furthermore, the benefit of ICD implantation is highly variable according to the different clinical stages of the disease. Therefore, further studies are needed to create a standardized diagnostic algorithm and appropriate treatment strategy for this special population.