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CARDIOLOGISTS IN DEVARABESANAHALLI BANGALORE Complex congenital heart disease: Fontan repair Anatomy and physiology Babies with a single ventricle or equivalent defect are often treated during childhood with a palliative operation to connect venous return directly to the pulmonary arteries—a Fontan repair. The prognosis is usually good: 75% of these patients survive at least 20 years. Complications Problems develop because of failure of the systemic ventricle, obstruction of the venous to pulmonary connection, atrial enlargement and AV valve regurgitation. Atrial arrhythmias become increasingly common. Sinus node dysfunction may necessitate pacing, which requires an epicardial electrode in most cases. Follow-up Echocardiography allows assessment of ventricular function and the AV valve. Obstruction in the Fontan connections can be examined with Doppler. MRI is increasingly useful for this assessment. Treatment Severe AV valve regurgitation, cyanosis and ventricular dysfunction are indications for intervention, including transplant or revision of the Fontan. Atrial arrhythmias can be treated with radiofrequency ablation. Pregnancy and contraception Pregnancy is possible in some patients with excellent Fontan function, good LV function and minimal AV valve regurgitation. Maternal risk is high if the Fontan is failing. There may be problems with the need to withdraw ACE inhibitors and with anticoagulation.
CARDIOLOGISTS IN BANGALORE Arrhythmias during pregnancy Women with congenital heart disease are at increased risk of supraventricular arrhythmias during pregnancy. Anti-arrhythmic drug treatment may be necessary for recurrent episodes. Digoxin may be useful for the control of heart rate but is often not effective. Beta-blockers and verapamil have been used for these patients and appear to be free of teratogenic effects.27 Amiodarone is a more effective anti-arrhythmic drug than these but should be reserved for intractable cases and used at the lowest useful dose.28 Sustained tachycardias (atrial flutter is the most common) are not well tolerated in pregnancy and DC cardioversion should be performed without delay for these patients.
DIABETIC SPECIALIST IN YALAHANKA Syncope and dizziness The history Syncope is a transient loss of consciousness resulting from cerebral anoxia, usually due to inadequate blood flow. Syncope may represent a simple faint or be a symptom of cardiac or neurological disease. Establish whether the patient actually loses consciousness and under what circumstances the syncope occurs—for example, on standing for prolonged periods or standing up suddenly (postural syncope), while passing urine (micturition syncope), on coughing (tussive syncope) or with sudden emotional stress (vasovagal syncope). Find out whether there is any warning such as dizziness or palpitations, and how long the episodes last. Recovery may be spontaneous or require attention from bystanders. Bystanders may also have noticed abnormal movements if the patient has epilepsy, but these can also occur in primary syncope. If the patient’s symptoms appear to be postural, enquire about the use of anti-hypertensive or anti-anginal drugs and other medications that may induce postural hypotension. If the episode is vasovagal, it may be precipitated by something unpleasant like the sight of blood, or it may occur in a hot crowded room; patients often feel nauseated and sweaty before fainting and may have had prior similar episodes, especially during adolescence and young adulthood. The diagnosis of this relatively benign and very common cause of syncope can usually be made from the history. Patients with very typical symptoms rarely require extensive investigations. If syncope is due to an arrhythmia there is often sudden loss of consciousness regardless of the patient’s posture. A history of rapid and irregular palpitations or a diagnosis of atrial fibrillation in the past suggests the possibility of sick sinus syndrome. These patients have intermittent tachycardia, usually due to atrial fibrillation, and episodes of profound bradycardia, often due to complete heart block. Chest pain may also occur if the patient has aortic stenosis or hypertrophic cardiomyopathy. Exertional syncope may occur in these patients because of obstruction to left ventricular outflow by aortic stenosis or septal hypertrophy . Dizziness that occurs even when the patient is lying down or that is made worse by movements of the head is more likely to be of neurological origin (vertigo), although recurrent tachyarrhythmias may occasionally cause dizziness in any position. Try to decide whether the dizziness is really vertiginous (there is a sensation of movement or spinning of the surroundings or the patient’s head), or whether it is a presyncopal feeling. A family history of syncope or sudden death raises the possibility of an ion channel abnormality (long QT syndrome, Brugada syndrome or hypertrophic cardiomyopathy). Attempts should be made to find out what the diagnosis was for the affected relatives. A past history of severe structural heart disease, especially heart failure,
CARDIOLOGIST IN DODDABOMMASANDRA, BANGALORE Cardiac rehabilitation Although rehabilitation has been a part of the management of patients following a myocardial infarction since the beginning of the last century, ideas have changed radically about the form this should take. In the early 1900s Sir Thomas Lewis insisted his patients remain in bed and be ‘guarded by day and night nursing and helped in every way to avoid voluntary movement or effort’. These severe restrictions were continued for at least six to eight weeks. The thinking was that complete rest would reduce the risk of aneurysm formation and avoid hypoxia that might cause arrhythmias. Even after discharge mild exertion was discouraged for up to a year and return to work was most unusual. In the 1970s periods of bed rest of between one and four weeks were enforced and patients remained in hospital for up to four weeks. It is now clear that this de-conditioning has many adverse physical and psychological effects. Patients with uncomplicated infarcts are now mobilised in hospital within a day or so of admission and are often discharged on the third day if successful primary angioplasty has been performed. Many hospitals provide a supervised rehabilitation program for patients who have had an infarct or episode of unstable angina. The program begins in hospital as soon as possible after admission. It includes a graded exercise regimen and advice about risk factor control. Such programs have many benefits for patients to help them to return quickly to normal life, including work and sexual activity. The supervised exercise regimen helps restore the patient’s confidence. There is clear evidence of the benefits of exercise for patients with ischaemic heart disease.54 Rehabilitation programs have been shown to be cost-effective. Well-conducted programs are tailored to individual patients’ needs and are very popular with many patients.55 There are often long-term exercise groups available for people who have completed the formal classes. Non-cardiac causes of chest pain Pulmonary embolism
BEST CARDIOLOGY HOSPITALS IN BANGALORE Cardiac failure Cardiac failure is an increasingly common condition affecting about 1% of the population but much higher proportions of older people. It is responsible for an increasing number of hospital admissions. The various aetiologies have been discussed above, but the most common cause is now ischaemic heart disease rather than hypertensive heart disease. This reflects the improved modern management of hypertension in the population. The definition of heart failure has always included reference to the inability of the heart to meet the metabolic needs of the body. The earliest concepts of heart failure were of inadequate cardiac pump function and associated salt and water retention. Treatment was aimed at improving cardiac contractility and removing salt and water from the body. In the 1970s the concept of after-load reduction was introduced. This was based partly on the realisation that vasoconstriction was part of the problem. This has led to the modern neuro-hormonal concept of heart failure. It is clear that many of the features of cardiac failure are a result of stimulation of the renin-angiotensin-aldosterone system and sympathetic stimulation. These responses of the body to the fall in cardiac output temporarily increase cardiac performance and blood pressure by increasing vascular volumes, cardiac contractility and systemic resistance. In the medium and longer term these responses are maladaptive. They increase cardiac work and left ventricular volumes and lead to myocardial fibrosis with further loss of myocytes. Most recently it has become clear that heart failure is also an inflammatory condition, with evidence of cytokine activation. Work is underway to establish a role for treatment of this part of the condition. Current drug treatment has been successful in blocking many of the maladaptive aspects of neuro-hormonal stimulation. Many of these treatments have become established after benefits have been ascertained in large randomised controlled trials. These trials have also led to the abandoning of certain drugs (often those that increase cardiac performance) that were shown to have a detrimental effect on survival (e.g. Milrinone). The principles of treatment of heart failure are as follows: 1 Remove the exacerbating factors. 2 Relieve fluid retention. 3 Improve left ventricular function and reduce cardiac work; improve prognosis. 4 Protect against the adverse effects of drug treatment. 5 Assess for further management (e.g. revascularisation, transplant). 6 Manage complications (e.g. arrhythmias). 7 Protect high-risk patients from sudden death.
THE CARDIOLOGISTS IN HSR LAYOUT Atrial fibrillation Atrial fibrillation is the most common sustained arrhythmia. The atrial activity consists of chaotic, small fibrillatory f waves at 400–700/minute. The ventricular response is usually 130–160/minute and is irregular. The ventricular response rate is slower if the patient has been treated with anti-arrhythmic drugs or if there is intrinsic AV nodal disease. When the response rate is slow, the AF is often reported as ‘controlled’ . very rapid ventricular response—more than 200/minute—may be seen in the presence of a bypass tract, like the bundle of Kent in WPW syndrome (Fig 3.24) or James fibres in LGL syndrome . The AF itself should never be reported as ‘fast’ because it always
THE BEST CARDIOLOGISTS IN YELAHANKA Pulmonary hypertension Pulmonary hypertension is an uncommon but important cause of dyspnoea. Many patients with this chronic and often severe illness will have raised pulmonary artery pressures as a result of a cardiac or respiratory illness. Other patients may present with increasing dyspnoea without an obvious cardiac or respiratory problem. Idiopathic (primary) pulmonary hypertension (IPH) is diagnosed only when other causes of pulmonary hypertension have been excluded. By definition, pulmonary hypertension is present when the mean pulmonary artery pressure (PAP) exceeds 25 mmHg at rest or 30 mmHg during exercise. The classification of pulmonary hypertension has been revised. The Venice classification was released in 2003. The term ‘primary pulmonary hypertension’ has been replaced with ‘idiopathic pulmonary hypertension’ Patients may have used fenfluramine or phenermine (appetite-suppressing drugs), or both. Use of these drugs for long periods has been associated with the greatest risk of developing pulmonary hypertension. In cases of IPH there may be a family history (6%; autosomal dominant condition with incomplete penetrance, 20–80%). The majority of familial cases are associates with a mutation on the BMPR2 gene. There may be associated symptoms including fatigue, chest pain, syncope and oedema. Cough and haemoptysis can be present. 270 PRACTICAL CARDIOLOGY The examination may help in assessing the severity of the patient’s dyspnoea as he or she undresses. Try to work out the patient’s functional class from the history and examination (p. 256) (NYHA I–IIII, often called the NYHA–WHO class when related to pulmonary hypertension). There may be signs of chronic lung disease or congenital heart disease, or specific signs of pulmonary hypertension and right heart failure (p. 257). Investigations are directed at finding an underlying reason for pulmonary hypertension— idiopathic pulmonary hypertension is a diagnosis of exclusion—and at assessing its severity and potential reversibility. The chest X-ray is abnormal in 90% of IPH patients. It may show pulmonary fibrosis or an abnormal cardiac silhouette—RV dilatation. There may be large proximal pulmonary arteries that appear ‘pruned’ in the periphery, and the heart may appear enlarged because of right ventricle dilatation) Respiratory function tests may show a normal, restrictive or obstructive pattern. Moderate pulmonary hypertension itself is associated with a reduction in the diffusing capacity for the carbon monoxide test (DLCO) to about 50% of predicted. On the ECG look for signs of right heart strain or hypertrophy, which are present in up to 90% of patients The blood gas measurements may show hypercapnia—elevated pCO2 in hypoventilation syndromes—but hypocapnia is more common in IPH because of increased alveolar ventilation. Mild hypoxia (reduction in pO2) may be present in IPH, and is more severe when pulmonary hypertension is secondary to lung disease. On CT pulmonary angiogram (CTPA), ventilation/perfusion (V/Q) lung scan or Doppler venograms look for a deep venous thrombosis (DVT) and PE and assess the extent of involvement of the pulmonary bed. A high-resolution CT scan of the lungs is the best way of looking for interstitial lung disease. The six-minute walking test predicts survival and correlates with the NYHA–WHO class. Reduction in arterial oxygen concentration of more than 10% during this test predicts an almost threefold mortality risk over 29 months. Patients unable to manage 332 m in six minutes also have an adverse prognosis.
CARDIOLOGY DOCTORS IN BANNERGHTTA ROAD ST elevation myocardial infarction Modern treatment of myocardial infarction has made a profound difference to the prognosis of this life-threatening condition. Before the introduction of CCUs, the expected in-hospital mortality of this condition was more than 20%. Monitoring and treatment of arrhythmias, and correction of biochemical and, where possible, haemodynamic complications in CCUs reduced this to about 12%. The ‘thrombolytic era’, which began with the publication of the results of the GISSI Trial, 31 has dramatically changed the approach to the management of infarction. The use of thrombolytic drugs (streptokinase in GISSI) reduced mortality to less than 10%, with greater benefit for those treated early.32 The addition of aspirin in later trials reduced mortality to about 7% and many CCUs now achieve mortality rates of 5 or 6%. There is no doubt that early treatment makes the greatest difference, but some benefit may be seen with treatment given up to 12 hours after the onset of symptoms of infarction. In centres where it can be performed primary angioplasty is the reperfusion treatment of choice for myocardial infarction. This is a grade A recommendation—level I evidence.33 Mortality rates below 5% can be achieved. The rationale for reperfusion treatment came with the realisation that infarction was caused by thrombosis within a coronary artery (a mechanism first proposed by Herrick in 191234) and that restoring blood flow before irreversible damage had occurred would be helpful. It has been known for a long time that the prognosis following myocardial infarction depends more than anything else on the amount of left ventricular damage that has occurred. For these reasons the early diagnosis of infarction has become very important. Patients with symptoms suggestive of infarction should have an ECG performed as soon as possible. If nondiagnostic changes are present, the tracing should be repeated frequently so that appropriate early decisions about treatment can be made if changes appear. The current ECG criteria for the use of reperfusion treatment (primary angioplasty
HEART SPECIALISTS IN SILKBOARD Complex congenital heart disease: conduits Anatomy and physiology Babies with a very abnormal right ventricular outflow tract such as pulmonary atresia can have a conduit fashioned to direct blood from the systemic veins more directly to the pulmonary arterial circulation or from a systemic artery to the pulmonary circulation. These conduits are made from veins or occasionally from Gortex. 368 PRACTICAL CARDIOLOGY Complications Conduits of all types have a limited life and tend to deteriorate after 10 years. These patients are also at risk of ventricular arrhythmias and heart block. Follow-up Patients need regular expert echocardiography to assess the conduit function. The conduit may deteriorate significantly before symptoms occur. Further treatment Conduit deterioration is usually an indication for further surgery although it can occasionally be treated with balloon dilatation. Pregnancy and contraception Pregnancy is well tolerated in patients with good conduit function. There are no particular problems with contraception. Sports Patients should avoid competitive and contact sports.