Welcome to Dr. Warrick's podcast channel. Warrick is a practicing cardiologist and author with a passion for improving care by helping patients understand their heart health through education. Warrick believes educated patients get the best health care. Discover and understand the latest approaches and technology in heart care and how this might apply to you or someone you love. My name's Dr. Warrick Bishop and I'd like to welcome you to my podcast and videocast station and of course I'd like to welcome you to the Healthy Heart Network. Today I'd like to talk a little bit about when hearts fail suddenly. We call this acute cardiac failure and this is really a medical emergency. With acute cardiac failure, acute simply means happening rapidly. Chronic means over a long period of time. So our language, acute, means occurring suddenly. With cardiac failure we see congestion. Congestion is really fluid, building up where it shouldn't, particularly in the lungs. When people present with acute cardiac failure, they have congestion. generally with fluid building up in the lungs giving rise to significant symptoms of shortness of breath. Their heart will be racing, their body will be responding as if they're under stress so they'll be sweaty and their skin will be shut down and clammy. Their blood pressure may have dropped and in fact often runs low because their body is shutting down in their pump. Their heart, the pump, is just not keeping that blood pressure up and often they won't be making much urine. If an individual turns up with fast heartbeat, low blood pressure, very short of breath, very unwell, poor production of urine, we call this cardiogenic shock. And this really is a serious, serious situation. We make the diagnosis as quickly as possible. Often it will be apparent from clinical examination. There will be evidence of fluid loading. The patient's central pressure, which is the jugular venous pressure, will be visible at the neck. The patient may be Making crackling noises, certainly listening to the back of the lungs will give characteristic features of crackles throughout. There may be swelling in the periphery as well. It's hard to know. It depends on the cause of the cardiac failure for that individual. But essentially we'll obtain a history. We'll examine the patient. That will give us some clues. We would obtain an ECG. which almost invariably would show tachycardia or a fast heart rate but it may also show abnormality of the ECG which would suggest abnormality of the underlying heart muscle and therefore point to the heart being a problem. As part of a workup of shortness of breath we would invariably get a chest x-ray. The heart may well be enlarged on the chest x-ray and give us another clue that the heart is implicated in this person's acute serious presentation. If possible we'd get an an urgent ultrasound of the heart and really ascertain exactly what's going on. How well is the heart muscle pumping or is there any major problem with the heart valves? Are they leaking profusely having come on suddenly with a mechanical failure? The ultrasound also gives us a chance to measure pressures within the circulation and particularly pressures within the lungs giving us some idea as to whether there's been back pressure within the lungs from poor functioning of philipentrical or even sometimes increased pressure within the lungs because clots have gone to the lungs and increased the resistance of blood passing through the lungs. Once we brought that patient in and started our diagnostic strategies out Our next step is to try and stabilise that patient as best as possible. Now we would bring that patient in and we tend to sit them up because if we sit them up the blood or congestion within their lungs at least drops to the bottom part of their lungs so that while they're breathing the less congested Higher parts of the lungs are getting good oxygen and we're improving the efficiency of the lungs. If we lay them down flat then that congestion can distribute right throughout the lung fields and decrease the efficiency of each breath. So we sit these people up. We establish good intravenous access so we put a line in so we can give drugs. and start to take bloods and see what's going on. Of course we collect all sorts of bloods as part of our work-up to try and understand if there's anemia or if there's an infection or some sort of electrolyte imbalance. We can also check bloods for things like a marker of cardiac failure which is brain natriuretic peptide which we've talked about before. If brain natriuretic peptide is really high then that really does support that this person's heart is the problem. We can also check a troponin which again gives us an indication of stress and strain on the heart. So we're getting in our intravenous access and we're pulling bloods to add to our initial assessment. If the patient is low in oxygen we often will give them oxygen to supplement as that often makes them feel more comfortable and helps with oxygenation through the tissues. We may do that through nasal specs or through a mask depending on how short of breath they are. If we do think it's cardiac failure then we'll often give people a little bit of something like morphine which is an opiate and the opiates we know diminish anxiety which of course if you are suffering with acute cardiac failure, you will understandably be anxious and we want to turn some of that anxiety down. Remember sympathetic drive is rarely your friend when your heart's playing up. So a little bit of morphine or opiate may take the edge off that anxiety. Sometimes it opens up the blood vessels in a favourable way as well, particularly on the venous side of the circulation. And that means that a little bit of venous pooling may reduce the amount of blood returning to the heart. and therefore give rise to less pressure on the heart, less work the heart has to do. As part of our support and stabilisation of a patient with cardiac failure we can also give those individuals ventilatory support. Now I talked about giving them oxygen through specs or through a mask but we can actually get masks that are applied to the face and cause a seal so that we can increase the pressure of the oxygen or gas that we're delivering to that individual. Those masks are continuous positive airway pressure ventilation and they allow us to literally push air into the lungs at a higher pressure than would occur if the person breathed in naturally for themselves. By increasing the pressure into the lungs we literally almost push the fluid out of the lungs. we also change the pressure within the thorax so if we're increasing the pressure within the thorax we're actually decreasing the work of the heart because by increasing the pressure of the thorax we're diminishing the gradient between the pressures within the thorax and the blood pressure and the heart inadvertently works a bit better we increase the pressures in the thorax we also reduce the amount of venous return coming in and so again we're offloading the heart So we can use positive pressure ventilation, ventilatory support to help these individuals with bad hearts and make them more comfortable in that acute setting. At the same time we would give people diuretics and we generally give it in through the vein because we know that there may be poor absorption through the gut during this time of sympathetic overdrive. Blood will be diverted from the gut and will be directed to other tissues. So giving in through the vein will make sure that those drugs get in place. And we would use the typical loop diuretics, the frisomide, which is a mainstay of making people diures or pass urine to help start to offload the congestion that that individual is suffering. Occasionally we'll also run in agents to lower blood pressure. This is only particularly the case if in this situation or in a particular situation the patient with a acute cardiac failure has raised or elevated blood pressure. If their blood pressure is low we don't want to lower it anymore. But vasodilators can certainly take pressure off the heart if there is room to move with the blood pressure. If the blood pressure is particularly low then in very certain circumstances we may choose to try and lift that blood pressure a little bit because blood pressure that's too low will be part of that cardiogenic shock symptom complex and may well lead to not only renal failure but other organ, end organ damage. We may choose to trickle in a little bit of what we call inotrate but essentially it's adrenaline type medication, adrenaline type substances to actually raise blood pressure and improve perfusion through the body. This has to be done very carefully because as we've alluded to more often than not the sympathetic nervous system is not your friend if your heart's not working well. For people who are really sick in tertiary and quaternal referral centres hospitals that are really highly geared with very specialised equipment there are mechanical things we can do to help these individuals with severe acute cardiac failure. One of the things we can do is literally suck fluid out of the circulation using the equivalent technique of dialysis. These people's kidneys may not be working in which case they may need true dialysis but if they don't need true dialysis we can use a a very similar related technique called ultrafiltration which is really a mechanism for us taking fluid out of the body using an extra machine where blood is taken, passes through the machine, less blood is returned to the individual. This is an extraordinarily powerful way of taking fluid out of the circulation for the individual. It doesn't require drugs and it doesn't require the kidneys to be working. We can also go further than that, we can put in assisting devices to help the heart pump and one of the amazing things we can put in is a thing called an intra-aortic balloon pump for counter pulsation. You don't need to remember all of that because it sounds pretty complicated but essentially we can literally slide a balloon that goes up into the aorta and that balloon expands and contracts in sync with the heartbeat. So when the heart is relaxed the balloon is expanding to make sure the blood pressure is maintained. When the heart is about to contract and release blood into the aorta that balloon collapses down to make it easier for the heart. It's an amazing bit of technology that expands and contracts and it's timed exquisitely with how the heartbeat is going in that individual. It can maintain blood pressure. is a very highly specialized intervention and only would be used in very particular situations. In the same space we're able to hook up the circulation. Again, a bit like dialysis where we take blood out of the patient, put it into a machine and run it back. We can do almost exactly the same as a bypass machine which is a transfer of oxygen through a membrane outside of the body. so that we can maintain oxygenation to that individual. We call that extra-corporal membrane oxygenation, but it's basically what we do on a bypass machine. Extra means outside of or above or excluding. Corporal means the body. membrane means that's what we exchange over and oxygen is what we use so extracorporeal membrane oxygen is called ECMO and that is a technique that can be used in these very critically unwell patients who we believe are able to be saved and brought back with a good quality of life. Lastly there are mechanical devices that literally piggyback onto the heart and can act as support pumps. These are left ventricular assist devices and are an amazing bit of technology that are really either implanted or walled pumps on the body to help support the circulation often used in situations where there's a feeling that the individual who's receiving the room left ventricular assist device may well progress to a heart transplant down the line or the possibility of that heart recovering by itself so that the assist device is no longer needed. So we've got a heap of stuff available for us but simple things first, good examination and history to try and ascertain where we are, simple tests in the accident, emergency, good IV access, deployment of oxygen, opiates, taking bloods, providing diuretic therapy, all makes perfect sense and then these second run of interventions, ventilatory support and beyond that mechanical circulatory support in extreme situations. As we're trying to make sure that we stabilise the patient we also need to try and make sure that we figure out what's caused the problem because if it's immediately reversible, there's an opportunity to make a difference there. Most commonly acute cardiac failure is in the setting of patients who have had previous cardiac failure and they've decompensated for some sort of reason. Perhaps an infection, perhaps anemia. It's going to be through our examination that we find out the answer to that. When we're thinking about acute cardiac failure though, it's pretty important. that we think of primarily cardiac causes and the most common of that is previous cardiac failure. The next most common is an acute coronary syndrome which is really the patient having a heart attack or lack of blood flow to the heart. This is extremely important because if we get that person to a coronary angiogram lab where we can undertake a procedure to open up that artery and get blood back to the heart we can rapidly improve left ventricular function, pump function and therefore really make a big difference in improving that person's outcome. We need to know if there's a rhythm abnormality. Again, this is a heart-related issue. Atrial fibrillation, particularly if the heart rate's very badly controlled on racing, will tip people into cardiac failure. Occasionally, other fast rhythms may do it as well, but the ECG will give us a clue there. It's also important to check for valve failure, as this is one of the cardiac-related causes of acute cardiac failure rupture of a valve or acute failure of a valve with torrential flow either way is a major cause of cardiac failure a significant cause that won't be ameliorated or fixed by any of these other maneuvers this person needs a proper diagnosis and needs to go to surgery if they have any hope the last cardiac related cause that I'll touch on is a condition called Tachosubo syndrome or broken heart syndrome. This is an interesting syndrome that I'll cover in more detail in another time but I'll leave it with you to think that if you have enough emotional discharge, enough stress of whatever sort, whether it's a confrontational stress, stress with illness, that the sympathetic nervous system can discharge so much energy that it literally shuts down the heart in a very particular and unique way. And that particular and unique way stops the distal part of the heart, the apex of the heart pumping properly and can put people into cardiac failure, let alone causing them chest pain and symptoms just like a heart attack as well. Once we've excluded heart related causes then it's pretty important when we're looking to try identify what's caused this acute cardiac failure to exclude infection to exclude anemia to exclude renal failure because renal failure could lead to retention of fluid and overload the heart and lastly we shouldn't forget pulmonary embolism which is a very common and a very significant complication which can give rise to features that look like cardiac failure predominantly however pulmonary embolism will present with features of cardiac failure affecting mainly the right hand side of the heart because the embolus gets caught in the lungs and it's the right hand side of the heart trying to pump past that. The left hand side of the heart receiving blood from the lungs in fact is not under much pressure at all but the patient can be very sick from that. So hearts that fail suddenly There's a lot to do to get these people stabilised and there's a lot to do to figure out exactly what's going on because until we know exactly what's going on we don't know how quickly we could reverse the problem. Acute cardiac failure, very serious condition. Acute cardiogenic shock, the extreme end of that condition. There's drugs, there's mechanical devices and there's investigations to help us get through it. I hope I've given you some interesting information to go through. If you have any queries or questions, as always, please drop me a note. If you have any thoughts for any future podcasts, again, please let me know. For now, I'm going to wish you the very best until next time. And of course, please don't die from a heart attack. Goodbye. You have been listening to another podcast from Dr. Warrick. Visit his website. at drWarrickbishop.com for the latest news on heart disease. If you love this podcast feel free to leave us a review.
