Hipertrofijska kardiomiopatija

Hypertrophic cardiomyopathy (HCM) is a disease of a thickened, but not dilated, left ventricle, that is not attributable to loading conditions. With a prevalence of around 1 in 500, HCM is the most common inherited condition of the cardiovascular system. In the majority of cases the disease is caused by one or more mutations of genes encoding for proteins of myocytic sarcomeres. These mutations are mostly inherited autosomal-dominantly, but can also arise de novo. Inherited metabolic diseases, neuromuscular disorders, amyloidoses, and adverse drug reactions are further possible etiologies of HCM. The pathophysiology of the disease is based on abnormalities of the myocytes, the interstitium and the microvasculature. Due to arrhythmias and hemodynamic abnormalities, which are shaped mainly by diastolic dysfunction and left ventricular outflow tract (LVOT) obstruction, patients develop the clinical manifestation of syncope, heart failure, as well as chest pain. Of special note is the occurrence of sudden cardiac death (SCD), which is often the first and only manifestation of the disease. In fact, HCM is the most common cause of SCD in the young. The diagnosis of HCM starts with the patient’s history, physical examination, and electrocardiogram (ECG) but it is mainly confirmed by echocardiographic findings. Further diagnostic modalities, which help in differentiating HCM from physiologic ventricular hypertrophy, fixed aortic stenosis, and other conditions, are cardiovascular magnetic resonance imaging (CMR), nuclear imaging, and genetic testing. As there is no cure of the underlying cause of the disease, the management focuses on the control of symptoms, improvement of the patients’ functional status, and prevention of SCD. Patients with HCM are advised to avoid competitive sports and intense physical exercise. Beta-blockers and calcium-channel blockers are the mainstay of medical management of heart failure symptoms, and chest pain. If the symptoms cannot be controlled adequately by medication, ventricular septal myectomy and alcohol septal ablation are two possible invasive procedures, which improve the functional status of the patient by relieving the outflow tract obstruction. Dual-chamber pacing using a short-programmed atrial ventricular delay is another modality for treatment of heart failure symptoms. The occurrence of a SCD can be prevented by implantation of an implantable cardioverter defibrillator (ICD).Hipertrofična kardiomiopatija (HCM) je bolest zadebljane, ali ne i proširene lijeve klijetke koja se ne može pripisati uvjetima njenog povećanog opterećenja. Sa učestalošću od oko 1:500, HCM je najčešća nasljedna bolest kardiovaskularnog sustava. U većini slučajeva bolest je uzrokovana mutacijom jednog ili više gena koji kodiraju proteine sarkomera kardiomiocita. Ove mutacije uglavnom se nasljeđuju autosomno-dominantno, ali mogu nastati i de-novo. Nasljeđene metaboličke bolesti, neuromuskularni poremećaji, amiloidoza i nuspojave nekih lijekova su rijeđi uzroci HCM-a. Patofiziologija bolesti se temelji na abnormalnostima kardiomiocita, intersticija i mikrocirculacije. Ritmološka nestabilnost, i poremećaj hemodinamike, koji je posljedica dijastoličke disfuncije miokarda i/ili opstrukcije izgonskog trakta lijeve klijetke (LVOT), uzrokuju kliničku sliku sinkope, zatajivanja srca i bolova u prsima. Posebno treba istaknuti iznenadnu srčanu smrt (SCD) kao posljedicu HCM-a. SCD je često prva i jedina manifestacija ove bolesti. Zapravo, HCM je najčešći uzrok SCD kod mladih. Dijagnoza HCM započinje anamnezom bolesnika, fizikalnim pregledim i elektrokardiogramom (EKG), a potvrđuje se uglavnom ehokardiografijom. Daljnji dijagnostički modaliteti koji pomažu u razlikovanju HCM-a od fiziološke hipertrofije ventrikula, fiksne aortne stenoze i drugih uzroka su magnetska rezonanca srca (CMR), nuklearno snimanje i genetičko testiranje. Kako se bolest u pravilu ne može etiološki lječiti, liječenje se fokusira na kontrolu simptoma, poboljšanje funkcionalnog stanja pacijenata i prevenciju SCD-a. Pacijentima s HCM-om preporučuje se izbjegavati natjecateljske sportove i intenzivnu fizičku aktivnost. Beta blokatori i blokatori kalcijevih kanala osnova su konzervativnog liječenja simptoma zatajenja srca i boli u prsima. Ako se simptomi ne mogu adekvatno nadzirati lijekovima, ventrikularna septalna miektomija i alkoholna septalna ablacija dva su invazivna postupka koja mogu poboljšati funkcionalni status pacijenta umanjujući opstrukciju LVOT-a. Dvokomorska elektrostimulacija s programiranjem kratkog atrioventrikulskog kašnjenja je mogući način liječenja bolesnika s opstrukcijom LVOT koji nisu reagirali na medikamentno liječenje, a nisu kandidati za ostale invazivne postupke. SCD se može spriječiti ugradnjom implantabilnog kardioverter defibrilatora (ICD)