Cardiophile MD » General

High altitude pulmonary edema (HAPE)

Johnson Francis — Thu, 12 Jan 2012 06:47:46 +0000

High altitude pulmonary edema is characterized by inhomogenous pulmonary vasoconstriction in response to reduced oxygen concentration in the inhaled air at high altitude. It may be noted that oxygen is one of the most potent pulmonary vasodilator, which is used therapeutically in the management of chronic pulmonary hypertension by way of nocturnal oxygen therapy. In high altitude pulmonary edema, the inhomogenous pulmonary vasoconstriction leads to elevated pulmonary capillary pressure and leakage of fluid into the alveoli. This is in fact a form of non cardiogenic pulmonary edema. Oxygen therapy and descend to lower altitudes are the logical answer for the treatment of high altitude pulmonary edema. Drugs like sildenafil, tadalafil and nifedipine have been used as pulmonary vasodilators in the management of high altitude pulmonary edema [Maggiorini M. Prevention and treatment of high-altitude pulmonary edema. Prog Cardiovasc Dis. 2010;52:500-6]. Dexamethasone is also considered useful in high altitude pulmonary edema [Maggiorini M et al. Both tadalafil and dexamethasone may reduce the incidence of high-altitude pulmonary edema: a randomized trial. Ann Intern Med. 2006;145:497-506]. A slow ascend of not more than three hundred meters per day above altitudes of two thousand five hundred meters, to allow acclimatization can be useful. Shorter stays of less than five days is also recommended in those prone for the disorder. Defective alveolar fluid clearance may be an important component in the pathogenesis of high altitude pulmonary edema [Scherrer U et al. New insights in the pathogenesis of high-altitude pulmonary edema. Prog Cardiovasc Dis. 2010;52:485-92]. Ultrasound lung comets have been detected as evidence of subclinical high altitude pulmonary edema in recreational climbers rather frequently [Pratali L et al. Frequent subclinical high-altitude pulmonary edema detected by chest sonography as ultrasound lung comets in recreational climbers. Crit Care Med. 2010;38:1818-23]. Portable hyperbaric chamber has also been used in the immediate management of high altitude pulmonary edema [Stream JO et al. Update on high-altitude pulmonary edema: pathogenesis, prevention, and treatment. Wilderness Environ Med. 2008;19:293-303].

Sydenham’s chorea (Rheumatic chorea)

Johnson Francis — Sat, 31 Dec 2011 14:49:58 +0000

Sydenham’s chorea is once of the major manifestations of rheumatic fever. It is a quasi purposive, non repetitive involuntary movement. Sydenham’s chorea is often associated with hypotonia and emotional instability. Rheumatic chorea (Sydenham’s chorea) is characterised by various signs like pronator sign, milking sing of the hand and jack in the box sign of the tongue. Sydenham’s chorea is a late manifestion of rheumatic fever in that it can occur months after a group A beta-hemolytic streptococcal infection, when other manifestations of acute phase like arthritis have disappeared. When the history is atypical or when only hemichorea is present investigations like a magnetic resonance imaging of the brain are needed to exclude other neuropathologies [Oosterveer DM et al. Sydenham's chorea: a practical overview of the current literature. Pediatr Neurol. 2010;43:1-6]. Immune mediated injury of the basal ganglia is thought to be the mechanism of Sydenham’s chorea. This is supported by the finding of antibodies against the neurons of the caudate nucleus. This results in imbalance between dopaminergic and cholinergic systems which may cause the involuntary choreiform movements. This explanation can account for the beneficial effects of certain drugs used in the treatment of chorea. Sodium valproate, carbamazapine and haloperidol have been used in those with disturbing chorea [Gordon N. Sydenham's chorea, and its complications affecting the nervous system. Brain Dev. 2009;31:11-4].

Phelbotomy in cyanotic congenital heart disease with hyperviscosity syndrome

Johnson Francis — Thu, 29 Dec 2011 06:06:31 +0000

Phelebotomy is often resorted to in patients with cyanotic congenital heart disease and symptoms of hyperviscosity due polycythemia which occurs in response to hypoxia which causes an increased erythropoetin level. In contrast, increased erythropoesis in polycythemia rubra vera occurs with normal or low erythropoetin levels. Hemoglobin levels and hematocrit are important considerations while planning venesection in those with symptoms of hyperviscosity. Hyperviscosity syndrome is characterized by impaired tissue oxygen delivery with symptoms like headache, visual disturbances, loss of concentration, paresthesia, muscle weakness, and fatigue. It should be remembered that dehydration and iron deficiency may precipitate hyperviscosity symptoms and just hydration may relieve symptoms in some cases [Rose SS et al. Cyanotic Congenital Heart Disease (CCHD) with Symptomatic Erythrocytosis. J Gen Intern Med. 2007; 22: 1775–1777]. Venesection in turn can lead to iron deficiency which can form a vicious cycle by increasing symptoms of hyperviscosity as the microcytes of iron deficiency (identified by lower mean corpuscular volume or MCV) are less deformable and can clog the microcirculation. This can also enhance the risk of stroke instead of reducing the risk. Hydroxyurea has been tried for reducing erythrocytosis in some refractory cases, though it has the risk of producing transient marrow suppresion which responds to dose reduction [Reiss UM et al. Hydroxyurea therapy for management of secondary erythrocytosis in cyanotic congenital heart disease. Am J Hematol. 2007;82:740-3]. Though the aim of phlebotomy in polycythemia rubra vera is to maintain hematocrit below 45%, most clinicians phelebotomize patients with cyanotic heart disease and polycythemia only if the hematocrit is above 65%. Phlebotomy works by reducing viscosity due to lower hematocrit, which in turn reduces peripheral vascualar resistance and increases cardiac output. Oxygen transport is improved and hence the symptoms of hyperviscosity are ameliorated. As mentioned above undue venesection has the potential of inducing iron deficiency and decompensated erythrocytosis, thereby defeating the very purpose of venesection.

Cor pulmonale – acute and chronic

Johnson Francis — Mon, 26 Dec 2011 15:08:23 +0000

In simple terms, cor pulmonale is heart disease secondary to lung disease which causes pulmonary hypertension. It is associated with right ventricular hypertrophy and / or dilatation, which eventually leads to right heart failure. Chronic obstructive pulmonary disease (COPD) is the most common cause of cor pulmonale, mainly because of its frequency. But more severe pulmonary hypertension may be noted in interstitial lung disease with idiopathic pulmonary fibrosis. Acute cor pulmonale usually occurs in the setting of acute pulmonary embolism. Acute exacerbation of COPD may be also associated with severe alveolar hypoxia leading to sudden rise in pulmonary arterial pressures and right heart failure. Since hypoxia is the most important cause of pulmonary hypertension in this setting, the natural treatment is with oxygen, which is a potent pulmonary vasodilator. Home oxgen therapy with either a conventional oxygen cylinder or an oxygen concentrator which derives oxygen from room air has been in use for reducing pulmonary arterial hypertension. Other alternatives for controlling pulmonary hypertension are prostacyclin, bosentan (endothelin receptor antagonist), sildenafil and nitric oxide. Of these bosentan and sildenafil being available for convenient oral usage, are gaining popularity. But we need good quality randomized controlled trials to establish the long term utility and safety of these drugs in the setting of chronic cor pulmonale. Acute cor pulmonale due to acute pulmonary embolism responds to thrombolytic therapy as well as antiocoagulation. Rheolytic thrombolysis is another option for acute pulmonary embolism. Surgical pulmonary thromboendarterectomy is useful in certain cases, even for chronic recurrent pulmonary embolism with severe pulmonary hypertension and right heart failure. Long term anticoagulation and inferior vena caval filters are useful in chronic recurrent pulmonary embolism causing cor pulmonale. Systemic therapy is needed in connective tissue disorders causing pulmonary hypertension.

Cardiac rupture

Johnson Francis — Mon, 26 Dec 2011 07:29:10 +0000

Cardiac rupture can be traumatic or spontaneous. Spontaneous rupture occurs most often after myocardial infarction. Traumatic rupture can be due to blunt trauma or penetrating injuries. Delayed rupture after blunt trauma with catastrophic results have also been described [Kanchan T et al. Blunt trauma to the chest- A case of delayed cardiac rupture. J Forensic Leg Med. 2012;19:46-7]. Myocardial ruptures can involve the free wall, papillary muscle or the ventricular septum. Papillary muscle rupture presents with severe pulmonary edema due to acute mitral regurgitation. Free wall rupture can be immediately fatal due to cardiac tamponade. Sometimes the rupture is contained by the adherent pericardium to form a pseudo aneurysm which can rupture at a later stage. Ventricular double rupture involving both free wall and the interventricular septum which could be repaired successfully has also been recorded in literature [Roberts JD et al. Can J Cardiol. 2011;27:868.e5-7.
Successful surgical repair of ventricular double rupture].

Apart from acute myocardial infarction, cardiac rupture has also been reported in Takotsubo cardiomyopathy which resembles myocardial infarction clinically and electrocardiographically [Kurisu S et al. Cardiac rupture in tako-tsubo cardiomyopathy with persistent ST-segment elevation. Int J Cardiol. 2011 Nov 4. [Epub ahead of print]]. A systematic review commented that those patients who developed cardiac rupture with Takotsubo cardiomyopathy were all females and significantly older [Kumar S et al. Cardiac rupture in takotsubo cardiomyopathy: a systematic review. Clin Cardiol. 2011;34:672-6]. This group identified eleven cases of cardiac rupture in Takotsubo cardiomyopathy from the literature and added one of their cases to make a total of twelve cases.

Loeffler’s endocarditis

Johnson Francis — Mon, 26 Dec 2011 06:10:32 +0000

Loeffler’s endocarditis was described by Wilhelm Loffler in 1936 [Loffler W. Endocarditis parietalis fibroplastica mit Bluteosinophilie. Ein eigenartiges Krankheitsbild. Schweizerische medizinische Wochenschrift, Basel, 1936, 66: 817-820] with eosinophilic infiltration in the endomyocardial region. It can cause a restrictive cardiomyopathy similar to endomyocardial fibrosis and is associated with hypereosinophilic syndrome. Large thrombi can occur in the ventricular cavity or attached to the valves. Restriction of movement of the mitral leaflets due to eosinophilic inflitration can cause severe mitral regurgitation [Tanaka H, et al. Surgical treatment for Loffler's endocarditis with left ventricular thrombus and severe mitral regurgitation: a case report. J Cardiol. 2006 Apr;47(4):207-13]. Such cases may need mitral valve replacement. Loeffler’s endocarditis can also present with vegetations on the valve leaflets without any involvement of the myocardium [Sen T et al. Hypereosinophilic syndrome with isolated Loeffler's endocarditis: complete resolution with corticosteroids. J Postgrad Med. 2008;54:135-7]. In this case there was good resolution of the vegetations with a two month course of corticosteroids.

Tricuspid valve involvement in Loeffler’s endocarditis also needs surgical treatment in certain cases [Imoto Y et al. Surgical treatment of tricuspid regurgitation caused by Loffler's endocarditis. Jpn J Thorac Cardiovasc Surg. 1999;47:570-3]. Arrhythmias like atrial flutter can sometimes be associated with Loeffler’s endocarditis. When there is endomyocardial involvement some authors call it as Loeffler’s endomyocarditis [Tamura M et al. A case of surgical treatment for Löffler's endomyocarditis. Jpn J Thorac Cardiovasc Surg. 1998;46:455-60].

ST segment and T wave changes in Loeffler’s endocarditis may mimic those in coronary artery disease [Maruyoshi H et al. Loffler's endocarditis associated with unusual ECG change mimicking posterior myocardial infarction. Heart Vessels. 2003;18:43-6]. Echocardiography is useful in Loeffler’s endocarditis for demonstration of valvular lesions including vegetations and thrombi as well as documenting endomyocardial involvement. Doppler echocardiography is useful in assessing severity of the regurgitant lesions.

Sinus of Valsalva aneurysm

Johnson Francis — Sun, 25 Dec 2011 05:10:37 +0000

Sinus of Valsalva aneurysms are clinically silent unless they produce symptoms due to compression of adjacent structures or rupture causing an abnormal track of blood flow. Usually they rupture into the right sided chambers so that it constitutes a left to right shunt. Majority of them, over two thirds, arise from the right sinus while some may arise from the non coronary sinus and very few (less than five percent) arise from the left sinus. Sinus of Valsalva aneurysms may be associated with ventricular septal defects, usually of the outlet (subpulmonic) or supracristal variety. Aortic regurgitation may be also associated in upto half of the cases. Progressive increase in the left to right shunt after rupture can cause heart failure and even mortality. Clinical findings will depend on the chamber into which it ruptures. Rupture into right sided chambers cause a superficial continuous murmur. Diastolic augmentation of the continuous murmur is characteristic of rupture into the right ventricle. This is because the track gets compressed in systole and the flow is better in diastole. Sinus of Valsalva aneurysm presents a ‘windsock’ appearance on echocardiography [Iadanza A et al. Echocardiography diagnosis of ruptured congenital right coronary sinus of Valsalva aneurysm into right ventricle. Eur J Echocardiogr. 2006; 7:387-389]. Even though earlier the treatment of a ruptured sinus of Valsalva aneurysm was entirely surgical, device closure is the norm in most cases now a days.

Cor triatriatum sinister and dexter

Johnson Francis — Sun, 25 Dec 2011 03:24:59 +0000

Cor triatriatum can be either cor triatriatum dexter or cor triatriatum sinister. Usually we mean cor triatriatum sinister when we say just cor triatriatum. Cor triatriatum means a heart with three atrial chambers instead of two. Cor triatriatum sinister has a partition in the left atrium so that there are two atrial chambers on the left side and one atrial chamber on the right side. In cor triatriatum dexter there is a partition in the right atrium so that there are two atrial chambers on the right side and one on the left. Cor triatriatum sinister may present as mitral stenosis [Slight RD et al. Cor triatriatum sinister presenting in the adult as mitral stenosis. Heart. 2003; 89: e26]. Original description of cor triatriatum dates back to as early as 1868 [Church WS. Congenital malformation of heart: abnormal septum in left auricle. Trans Path Soz. 1868;19:188-190]. In cor triatriatum sinister (also called cor triatriatum sinistrum) the upper chamber usually receives the pulmonary venous inflow while the lower chamber has the left atrial appendage, fossa ovalis and connects to the mitral valve. It is when the separation between the two chambers is restrictive that they can present like mitral stenosis with left ventricular inflow obstruction. Cor triatriatum dexter (also called cor triatriatum dextrum) is much rarer than cor triatriatum sinister. As on the left side, the upper chamber receives the venous inflow from the superior and inferior vena cavae and the lower portion has the right atrial appendage and the connection with the tricuspid valve.

Ambulatory blood pressure (BP) monitoring

Johnson Francis — Wed, 07 Dec 2011 07:04:19 +0000

It is well known that blood pressure of an individual can wary widely at various times of the day. There is also a so called “white coat effect” in which blood pressure is elevated when recorded in the medical setting. Ambulatory monitoring and home monitoring are two methods which have been developed to assess the ‘true’ blood pressure in an ideal setting. Ambulatory recordings have been attempted even over forty years back, though it has come into routine use only recently. This is because of the current availability of easy to wear ambulatory monitoring equipments which measure blood pressure by the oscillometric method. A blood pressure cuff applied over the arm is connected by tubings to the inflation and recording device kept in a belt pouch. The devices can be programmed to measure blood pressure at varying intervals like 15 or 30 minutes through out the day and night. The subject is asked to avoid movements of the arm while the cuff inflation and deflation are going on. The readings can be analyzed by a computer software to get average blood pressure, diurnal rhythm of blood pressure variation and the blood pressure variability. Recent guidelines have started including average blood pressure values to guide management. The average blood pressure is thought to determine the target organ damage better than the clinic measured blood pressure.

It is possible to calculate the level of dip in pressures during sleep so as to classify individuals into dippers, extreme dippers, non dippers and reverse dippers. Dip = (1-Systolic BP during sleep/Sysolic BP while awake), expressed as a percentage. Negative value indicates reverse dipper. Values less than 10 percent are considered in the non-dipper range, while 10-20% range constitutes the dippers and more than 20% constitute the extreme dippers. The morning surge in blood pressure has been linked to cardiovascular events and stroke.

dal-PLAQUE: phase 2b study of dalcetrapib which increases HDL cholesterol

Johnson Francis — Sat, 26 Nov 2011 13:00:26 +0000

Initial studies of increasing HDL cholesterol with cholesteryl ester transfer protein (CETP) inhibitor torcetrapib were a failure and further development of the molecule was halted. Now another CETP modulator dalcetrapib has been evaluated in the dal-PLAQUE phase 2b trial regarding safety and efficacy [Fayad ZA et al. Safety and efficacy of dalcetrapib on atherosclerotic disease using novel non-invasive multimodality imaging (dal-PLAQUE): a randomised clinical trial. The Lancet, Volume 378, Issue 9802, Pages 1547 - 1559, 29 October 2011]. Multi modality imaging was used to assess the structural and inflammatory indices as primary end points. It was a randomized multicentric trial of patients with or high risk of coronary artery disease with either dalcetrapib 600 milligrams daily or placebo. Total vessel area, wall area, wall thickness, and normalised wall index of carotids were assessed using magnetic resonance imaging after two years. 18F-fluorodeoxyglucose (18F-FDG) positron emission tomographic (PET/CT) assessment of arterial inflammation within an index vessel (right carotid, left carotid, or ascending thoracic aorta) was done after 6 months. Total of one hundred and thirty patients were included in the study. Unlike in the case of torcetrapib, dalcetrapib did not increase the blood pressure. The authors found that there was no evidence of a pathological effect related to the arterial wall with dalcetrapib at two years. There is also a suggestion of beneficial vascular effects including the reduction in total vessel enlargement over two years. The long term safety and clinical efficacy of dalcetrapib needs to analysed further.