An elevated<unk>  is the classic sign of<unk>  hypertension (e.g. right-sided heart failure).<unk>  elevation can be visualized as<unk><unk>  distension, whereby the<unk>  is visualized at a level of the neck that is higher than normal. The<unk>  is often used to assess the central<unk>  pressure in the absence of invasive measurements (e.g. with a central<unk>  catheter, which is a tube inserted in the neck veins). A 1996 systematic review concluded that a high<unk>  makes a high central<unk>  pressure more likely, but does not significantly help confirm a low central<unk>  pressure. The study also found that agreement between doctors on the<unk>  can be poor, calling into question its reliability as a clinical decision-making tool. Similarly, a 2016 study examined the use of<unk>  measurements by clinical examination in the evaluation of central<unk>  pressure in patients with heart failure. This study found that<unk>  examination was not consistent with actual central<unk>  pressures, such that it was unreliable both for ruling in and ruling out heart failure.<unk>  measurement was especially unreliable in patients with high body fat. Additionally, it was noted that clinicians seemed to "extrapolate"<unk>  measurements from other, more easily examinable findings (like lung auscultation, body weight, heart rate, brachial blood pressure, and chest radiography findings). The paradoxical increase of the<unk>  with inspiration (instead of the expected decrease) is referred to as the Kussmaul sign, and indicates impaired filling of the right ventricle. The differential diagnosis of Kussmaul's sign includes constrictive pericarditis, restrictive cardiomyopathy, pericardial effusion, and severe right-sided heart failure. Certain wave form abnormalities, include cannon a-waves, or increased amplitude 'a' waves, are associated with AV dissociation (third degree heart block), when the atrium is contracting against a closed tricuspid valve, or even in ventricular tachycardia. Another abnormality, "c-v waves", can be a sign of tricuspid regurgitation. The absence of 'a' waves may be seen in atrial fibrillation. An exaggerated "y" wave or diastolic collapse of the neck veins from constrictive pericarditis is referred to as Friedreich's sign. * Raised<unk> , normal waveform * Bradycardia * Fluid overload * Heart failure * Raised<unk> , absent pulsation * Superior vena cava syndrome * Large 'a' wave (increased atrial contraction pressure) * Tricuspid stenosis * Right heart failure * Pulmonary hypertension * Cannon 'a' wave (atria contracting against closed tricuspid valve) * Atrial flutter * Premature atrial rhythm (or tachycardia) * Third degree heart block * Ventricular ectopics * Ventricular tachycardia * Absent 'a' wave (no unifocal atrial depolarisation) * Atrial fibrillation * Large 'v' wave (c–v wave) * Tricuspid regurgitation * Absent 'x' descent * Tricuspid regurgitation (sometimes 'x' wave is replaced by a positive wave) * Prominent 'x' descent * Cardiac tamponade * Slow 'y' descent * Tricuspid stenosis * Cardiac tamponade * Prominent & deep 'y' descent * Constrictive pericarditis * Parodoxical<unk>  (Kussmaul's sign:<unk>  rises with inspiration, drops with expiration) * Pericardial effusion * Constrictive pericarditis * Pericardial tamponade
Jugular venous pressure
Plateau pressure
Pulse pressure
Segmental blood pressure
Pressure reactivity index
Arterial resistivity index
Central venous pressure
Mean arterial pressure