The drug that is closest to the heart of cardiologists and most widely prescribed for a variety of indications. Literally responsible for saving millions of lives every year and making people survive through the painful angina and even drag them out of the hopelessness of myocardial infarction. The drug that is used most extensively for high blood pressure and which has given a new lease of life to patients with cardiac failure. The drug that is being used for anxiety and migraine in millions of patients in the general practice – this drug is called BETA BLOCKER.
Let’s explore the role of this group in many cardiac problems starting from high blood pressure to heart failure and heart attack.
HYPERTENSION AND BETA BLOCKERS:
Beta-blockers makes the heart beat more slowly and less strongly. They work by blocking the action of nerves supplying the heart that release a chemical called Noradrenalin. This helps to control the rhythm and force of heart muscle movement. It also effects and tones down the central sympathetic activity. Beta blockers have been in the forefront of antihypertensive arsenal for the last two decades. They have been shown to be highly effective in reducing systolic and diastolic blood pressure specially in persons with high sympathetic drive or who are tense. They are effective in reducing total death rate, strokes and kidney failure in patients with high blood pressure. Beta blockers can effectively reduce the thickness of muscle of heart due to high blood pressure. Beta blockers are well tolerated by a majority of patients and have been found to very safe in all age groups and both genders. They have a special role to play in patients with compelling indications like angina, heart attack, and heart failure. This is the only group of drugs to show reduction in heart attacks in white, non smoker males.
Being highly effective drugs with extremely safe profile, the group has earned a special place, for itself in the drugs used for hypertension. These are the most commonly used and often the drug of first choice for this indication.
ANGINA AND BETA BLOCKERS
The commonest presentation of Coronary artery disease – when a person develops blockages in the blood supply of heart, is angina. Physical or mental stress leads to increasing heart rate and blood pressure, which leads to chest pain called angina. Beta-blocker slow the heart rate and reduce the heart’s workload. When the heart does not have to work as hard, it requires less oxygen. This in turn can help relieve or prevent chest pain (angina). To treat and prevent these pains, beta blockers have proved to be very effective. Beta-blockers are often used with the medications to treat angina. Beta blockers are the drugs of first choice in most patients presenting with angina. There is ample data to support its role in angina where it decreases the frequency of angina episodes and increase effort tolerance/ exercise capacity. The severity of anginal attacks decreases markedly with Beta blockers.
Role of beta blockers in Heart attack:
Heart attack is a common presentation of coronary heart disease. Here the blood supply to a part of heart blocks completely causing death of that portion of heart. There are two ways to approach a patient with myocardial infarction. The first one is opening the blockages in arteries to re-initiate blood going to the heart, the other one is decreasing the demand of blood supply to muscles of heart and this is what this magical drug does. Beta blockers have been shown to reduce the size of myocardial infarct – dead portion of heart in animal and human models. Beta blockers reduce lipolysis, that is the break down of fats. Beta-blockers given within hours of the start of a heart attack reduce both the risk of death and recurrent heart attack. They have well established anti-ischemic, anti-arrhythmic and anti-hypertensive effects. Large trials have shown impressive reduction of morbidity and mortality with oral and intravenous beta blockers. Evidence strongly suggests that most people should take beta-blockers for at least 6 months and may be two years after a heart attack, and probably longer to get the most benefit. It applied to both genders regardless of age. It is a must for all those who suffer from hypertension. The intake is oral and should be taken continually for about two years. Almost all drugs show similar effects, although water soluble beta blockers have a clear advantage over others. But for people who have asthma and hypotension, this drug is not recommended, however controlled diabetes is not a contraindication to beta blockers as the benefits outweigh the hazards.
Role of Beta-Blockers in Heart Failure
Heart failure is a significant public health problem effecting 15 million people world wide. There has been an increasing incidence of heart failure in contrast to the decreasing incidence of heart diseases. The associated hazards as found in Framingham study, mortality rate 17% in one year, 30% in two years and 50% in five years.
For the past 40 years medical students have been taught to avoid Beta Blockers in heart failure. Beta Blockers work by blocking adrenaline which increases force of contraction of heart muscle and improve its performance. Beta blockers are like double edged sword. Due to their negative effects on heart rate and contractility, they can worsen the heart failure but, used properly and judiciously they ameliorate the patients status and have salutary effects on the clinical status, exercise capacity and reduce death rate. This has been one of the most wonderful ‘rediscovery’ of the effects of beta blockers. This is also an example of how clinical experience and experimentation can alter the course of action and carve new place.
Many large trials have been conducted to evaluate the efficacy of beta blockers in large populations with mild, moderate and severe heart failure and patients with left ventricular dysfunction after a heart attack. There was a definite and marked reduction in mortality. All cause mortality and hospitalization was reduced significantly. Hospitalization due to any cause was reduced markedly.
Who are the patients that will benefit from beta blockers therapy? All patients with mild, moderate or severe but compensated heart failure on standard treatment of ACE Inhibitors and diuretics are candidates for beta blockers. There are important points to be kept in mind as only stable patients should start beta blockers. Preferably, doses should not be changed of ACE Inhibitors for one month and diuretics for 2 weeks. Ideally patients should not have required intravenous supporting drugs in the last one month.
This is an exercise that requires persistence and patience! One has to start with a very small does and then the dose has to be increased very slowly over weeks while monitoring heart failure status, blood pressure and heart rate. Some patients may deteriorate initially, that is why persistence is very important and patients have to be encouraged to adhere to the therapy. Many patients may not see any change in their clinical status initially that is why patience is required and patients have to be motivated to hold on to the treatment.
Various trials have now documented that Beta Blockers used carefully reduce heart failure symptoms and improve the quality of life. Beta blockers have been shown to reduce the risk of all cause mortality, such as sudden death and death from progression of heart failure. Beta blockers have been effective in reducing hospitalization. Compelling evidence now exists to support the safety and efficiency of Beta Blocker therapy in heart failure.
What are the specific side effects? Patients may complains of fatigue, slow heart rate and low blood pressure. Speciation caution has to be exercised in patients with reactive airway disease and decompensated stated.
Tachycardias:
Many patients with structurally normal heart have the propensity to develop very fast beating of heart – tachycardia, presenting as palpitations, fluttering or loss of consciousness in severe cases. Because of their effects on sinus node and AV node – two important pulse generators, this fast beating can be effectively controlled. The drug may be used intravenously for immediate effects and it is effective in most cases. It is used in oral preparation for the prevention of further attacks.
Other cardiac problems:
Beta blockers have found an application in many other fields.
· It is used to relieve the obstruction in patients presenting with severe outflow obstruction like right pumping chamber outflow obstruction.
· It is effective in reducing heart rate where patient has very fast heart rate specially accompanied by obstruction like narrowing of the valve – door between left storing and pumping chambers.
· It is used effectively in reducing rapid and powerful contraction in patients with markedly thickened interventricular septum called hypertrophic obstructive cardiomyopathy HOCM.
Miscellaneous:
There was a time when newer indications were found for the usage of beta blockers every week. The drug was tried and many times quite successfully in many scenarios outside the world of cardiology.
· The drug alleviates anxiety and are used by many for allaying anxiety in stressful situations like presentations, examinations and speeches. They do not impair intellectual powers but reduce the ‘fast beating’ of heart and the unwanted ‘tremors’ and ‘cold sweat’. These drugs are used extensively by psychiatrists, all over the world, for reducing anxiety and counter the tachycardic effects of some drugs.
· They are used for tremors – mainly senile tremors.
· Many people with migraine (headaches) have been able to reduce the severity and frequency of episodes.
· Beta blockers are used in patients with liver disease like Cirrhosis for reduction of pressure in liver.
· They are used in patients with thyroid gland hyperactivity called thyrotoxicosis for controlling their symptoms.
Side Effects
Like all potent drugs beta blockers have side effects and pros and cons have to be weighed for all clinical conditions and patients. Side effects of beta-blockers may include lack of energy or drive, fatigue, vivid dreams and erection problems (impotence). It can decrease blood flow to fee and hands, causing them to feel cold and increase leg pain brought on by exertion (intermittent claudication). May cause dizziness and lightheadedness, more likely to occur when started or when the dose is increased. In people with diabetes, beta-blockers can insignificantly increase blood sugar levels. More importantly beta blockers may mask warning signs of low blood sugar, such as increase in pulse rate and sweating. Beta-blockers may worsen medical conditions such as asthma, heart failure, and certain heart arrhythmias. Beta-blockers should not be stopped without first discussing with the doctor. The risk of heart attack may be increased when beta-blockers are stopped suddenly.
Beta blockers are drugs with multiple actions and have been used in many cardiac diseases like high blood pressure, angina, heart attack and heart failure. They have wide-spread applications in non cardiology world. By and large they are well tolerated and have certain side effects which have to be watched.
_____________________________________________
Ref: Heal Thy Heart written by Prof: Dr. Muhammad Hafizullah
Let’s explore the role of this group in many cardiac problems starting from high blood pressure to heart failure and heart attack.
HYPERTENSION AND BETA BLOCKERS:
Beta-blockers makes the heart beat more slowly and less strongly. They work by blocking the action of nerves supplying the heart that release a chemical called Noradrenalin. This helps to control the rhythm and force of heart muscle movement. It also effects and tones down the central sympathetic activity. Beta blockers have been in the forefront of antihypertensive arsenal for the last two decades. They have been shown to be highly effective in reducing systolic and diastolic blood pressure specially in persons with high sympathetic drive or who are tense. They are effective in reducing total death rate, strokes and kidney failure in patients with high blood pressure. Beta blockers can effectively reduce the thickness of muscle of heart due to high blood pressure. Beta blockers are well tolerated by a majority of patients and have been found to very safe in all age groups and both genders. They have a special role to play in patients with compelling indications like angina, heart attack, and heart failure. This is the only group of drugs to show reduction in heart attacks in white, non smoker males.
Being highly effective drugs with extremely safe profile, the group has earned a special place, for itself in the drugs used for hypertension. These are the most commonly used and often the drug of first choice for this indication.
ANGINA AND BETA BLOCKERS
The commonest presentation of Coronary artery disease – when a person develops blockages in the blood supply of heart, is angina. Physical or mental stress leads to increasing heart rate and blood pressure, which leads to chest pain called angina. Beta-blocker slow the heart rate and reduce the heart’s workload. When the heart does not have to work as hard, it requires less oxygen. This in turn can help relieve or prevent chest pain (angina). To treat and prevent these pains, beta blockers have proved to be very effective. Beta-blockers are often used with the medications to treat angina. Beta blockers are the drugs of first choice in most patients presenting with angina. There is ample data to support its role in angina where it decreases the frequency of angina episodes and increase effort tolerance/ exercise capacity. The severity of anginal attacks decreases markedly with Beta blockers.
Role of beta blockers in Heart attack:
Heart attack is a common presentation of coronary heart disease. Here the blood supply to a part of heart blocks completely causing death of that portion of heart. There are two ways to approach a patient with myocardial infarction. The first one is opening the blockages in arteries to re-initiate blood going to the heart, the other one is decreasing the demand of blood supply to muscles of heart and this is what this magical drug does. Beta blockers have been shown to reduce the size of myocardial infarct – dead portion of heart in animal and human models. Beta blockers reduce lipolysis, that is the break down of fats. Beta-blockers given within hours of the start of a heart attack reduce both the risk of death and recurrent heart attack. They have well established anti-ischemic, anti-arrhythmic and anti-hypertensive effects. Large trials have shown impressive reduction of morbidity and mortality with oral and intravenous beta blockers. Evidence strongly suggests that most people should take beta-blockers for at least 6 months and may be two years after a heart attack, and probably longer to get the most benefit. It applied to both genders regardless of age. It is a must for all those who suffer from hypertension. The intake is oral and should be taken continually for about two years. Almost all drugs show similar effects, although water soluble beta blockers have a clear advantage over others. But for people who have asthma and hypotension, this drug is not recommended, however controlled diabetes is not a contraindication to beta blockers as the benefits outweigh the hazards.
Role of Beta-Blockers in Heart Failure
Heart failure is a significant public health problem effecting 15 million people world wide. There has been an increasing incidence of heart failure in contrast to the decreasing incidence of heart diseases. The associated hazards as found in Framingham study, mortality rate 17% in one year, 30% in two years and 50% in five years.
For the past 40 years medical students have been taught to avoid Beta Blockers in heart failure. Beta Blockers work by blocking adrenaline which increases force of contraction of heart muscle and improve its performance. Beta blockers are like double edged sword. Due to their negative effects on heart rate and contractility, they can worsen the heart failure but, used properly and judiciously they ameliorate the patients status and have salutary effects on the clinical status, exercise capacity and reduce death rate. This has been one of the most wonderful ‘rediscovery’ of the effects of beta blockers. This is also an example of how clinical experience and experimentation can alter the course of action and carve new place.
Many large trials have been conducted to evaluate the efficacy of beta blockers in large populations with mild, moderate and severe heart failure and patients with left ventricular dysfunction after a heart attack. There was a definite and marked reduction in mortality. All cause mortality and hospitalization was reduced significantly. Hospitalization due to any cause was reduced markedly.
Who are the patients that will benefit from beta blockers therapy? All patients with mild, moderate or severe but compensated heart failure on standard treatment of ACE Inhibitors and diuretics are candidates for beta blockers. There are important points to be kept in mind as only stable patients should start beta blockers. Preferably, doses should not be changed of ACE Inhibitors for one month and diuretics for 2 weeks. Ideally patients should not have required intravenous supporting drugs in the last one month.
This is an exercise that requires persistence and patience! One has to start with a very small does and then the dose has to be increased very slowly over weeks while monitoring heart failure status, blood pressure and heart rate. Some patients may deteriorate initially, that is why persistence is very important and patients have to be encouraged to adhere to the therapy. Many patients may not see any change in their clinical status initially that is why patience is required and patients have to be motivated to hold on to the treatment.
Various trials have now documented that Beta Blockers used carefully reduce heart failure symptoms and improve the quality of life. Beta blockers have been shown to reduce the risk of all cause mortality, such as sudden death and death from progression of heart failure. Beta blockers have been effective in reducing hospitalization. Compelling evidence now exists to support the safety and efficiency of Beta Blocker therapy in heart failure.
What are the specific side effects? Patients may complains of fatigue, slow heart rate and low blood pressure. Speciation caution has to be exercised in patients with reactive airway disease and decompensated stated.
Tachycardias:
Many patients with structurally normal heart have the propensity to develop very fast beating of heart – tachycardia, presenting as palpitations, fluttering or loss of consciousness in severe cases. Because of their effects on sinus node and AV node – two important pulse generators, this fast beating can be effectively controlled. The drug may be used intravenously for immediate effects and it is effective in most cases. It is used in oral preparation for the prevention of further attacks.
Other cardiac problems:
Beta blockers have found an application in many other fields.
· It is used to relieve the obstruction in patients presenting with severe outflow obstruction like right pumping chamber outflow obstruction.
· It is effective in reducing heart rate where patient has very fast heart rate specially accompanied by obstruction like narrowing of the valve – door between left storing and pumping chambers.
· It is used effectively in reducing rapid and powerful contraction in patients with markedly thickened interventricular septum called hypertrophic obstructive cardiomyopathy HOCM.
Miscellaneous:
There was a time when newer indications were found for the usage of beta blockers every week. The drug was tried and many times quite successfully in many scenarios outside the world of cardiology.
· The drug alleviates anxiety and are used by many for allaying anxiety in stressful situations like presentations, examinations and speeches. They do not impair intellectual powers but reduce the ‘fast beating’ of heart and the unwanted ‘tremors’ and ‘cold sweat’. These drugs are used extensively by psychiatrists, all over the world, for reducing anxiety and counter the tachycardic effects of some drugs.
· They are used for tremors – mainly senile tremors.
· Many people with migraine (headaches) have been able to reduce the severity and frequency of episodes.
· Beta blockers are used in patients with liver disease like Cirrhosis for reduction of pressure in liver.
· They are used in patients with thyroid gland hyperactivity called thyrotoxicosis for controlling their symptoms.
Side Effects
Like all potent drugs beta blockers have side effects and pros and cons have to be weighed for all clinical conditions and patients. Side effects of beta-blockers may include lack of energy or drive, fatigue, vivid dreams and erection problems (impotence). It can decrease blood flow to fee and hands, causing them to feel cold and increase leg pain brought on by exertion (intermittent claudication). May cause dizziness and lightheadedness, more likely to occur when started or when the dose is increased. In people with diabetes, beta-blockers can insignificantly increase blood sugar levels. More importantly beta blockers may mask warning signs of low blood sugar, such as increase in pulse rate and sweating. Beta-blockers may worsen medical conditions such as asthma, heart failure, and certain heart arrhythmias. Beta-blockers should not be stopped without first discussing with the doctor. The risk of heart attack may be increased when beta-blockers are stopped suddenly.
Beta blockers are drugs with multiple actions and have been used in many cardiac diseases like high blood pressure, angina, heart attack and heart failure. They have wide-spread applications in non cardiology world. By and large they are well tolerated and have certain side effects which have to be watched.
_____________________________________________
Ref: Heal Thy Heart written by Prof: Dr. Muhammad Hafizullah
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