This is a disorder where the tricuspid valve fails to close properly, allowing backward flow of blood. Other structural defects which lead to RVH include tetralogy of Fallot, ventricular septal defects, pulmonary valve stenosis, and atrial septal defects. RVH is also associated with abdominal obesity, elevated fasting blood glucose, high systolic blood pressure, and fractional shortening of the left ventricular mid-wall.Other risk factors for RVH include smoking, sleep apnea, and strenuous activity. These increase the risk of heart and lung disease and hence RVH. Pathophysiology
Right ventricular hypertrophy can be both a physiological and pathophysiological process. It becomes pathophysiological (damaging) when there is excessive hypertrophy. The pathophysiological process mainly occurs through aberrant signalling of the neuroendocrine hormones; angiotensin II, endothelin-1 and the catecholamines (e.g. noradrenaline). Angiotensin-II and endothelin-1
Angiotensin-II and endothelin-1 are hormones that bind to the angiotensin (AT) and endothelin (ET) receptors. These are G-protein coupled receptors that act via internal signalling pathways. Through several intermediates, these pathways directly or indirectly increase reactive oxygen species (ROS) production causing accumulation in myocardial cells. This can subsequently induce necrotic cell death, fibrosis, and mitochondrial dysfunction.This has been demonstrated in animal studies. Protein Kinase C (PKC) is an intermediate molecule in the signalling pathway and mice lacking PKC shown resistance to heart failure compared to mice overexpressing PKC which shown heart dysfunction.Targeting the renin–angiotensin (RAAS) system (using angiotensin-converting enzyme inhibitors and angiotensin-receptor blockers) are a well-recognized clinical approach for reversing maladaptive cardiac hypertrophy independently of blood pressure. Catecholamines
Catecholamines levels increase due to increased sympathetic nervous system activity.
A subungual hematoma is a collection of blood (hematoma) underneath a toenail or fingernail. It can be extremely painful for an injury of its size, although otherwise it is not a serious medical condition. Nature
A laceration of the nail bed causes bleeding into the constricted area underneath the hard nail plate. The blood pools under the nail, giving a reddish, brownish, blueish, or grey/blackish discoloration. The blood puts pressure to the nailbed causing pain which can be throbbing in quality and disappears when the pressure on the nail bed is relieved.Subungual hematomas typically heal without incident, though infection may occur. The pressure of the blood blister may cause separation of nail plate from the nail bed (onycholysis), but the nail should not be pulled off, as this can cause scarring of the nailbed and deformed nails. Nail discolouration may last some months.The nail plate may also become thicker and more brittle as a result of the injury (onychochauxis). The deformed nail plate will gradually grow out and be replaced by new, normal-appearing nail plate in several months time. Infrequently, the nail may become painful and require surgical drainage. Causes
The condition is caused by a traumatic injury, such as slamming a finger in a door, or from sports activities, especially those involving sudden accelerations, such as soccer, basketball, and tennis,  or going downhill, such as running or hiking rugged terrain, and ill-fitting footwear. : 52, 135 Repeatedly thrusting the toes against a shoes toe box can cause a subungual hematoma called joggers toe, runners toe, or black toenail.