Acute chest pain is one of the most common presentations in primary care - and also one of the most concerning, as several potentially fatal pathologies may present in this manner. In this patient, note the duration, character and radiation of the pain, as well as the associated dyspnea and palpitations - an acute coronary syndrome (ACS) needs to be ruled out urgently. However, serial ECGs are found to be normal, making an ACS clinically less likely. Cardiac dysrhythmias can also present in this manner; note in particular the history of similar episodes in the past, where he felt 'worried about a serious outcome'; this might have been episodes of ventricular arrhythmia (where patients may experience a 'feeling of doom'). However, the ECGs are in sinus rhythm - even though he is actively complaining of palpitations. Thus, an arrhythmic episode is highly unlikely. Hypoglycemic attacks may also present with similar symptoms, but are excluded by the normal random blood glucose level; mitral valve prolapse is also excluded by the normal echocardiogram, and hyperthyroidism by the normal thyroid function tests. A pheochromocytoma is another rare possibility; however, during an episode, one would expect to detect tachycardia, some degree of elevation of blood pressure, and sweating; this is as opposed to the normal examination findings in this patient. Now that serious organic disease is excluded, his symptoms lend themselves towards another, non-organic diagnosis: a panic attack. Note that his presenting episode contains 4 common symptoms of the condition. Furthermore, note that the episodes recur unexpectedly; he has persistent concern of recurrence; and he has developed avoidance - a maladaptive behaviour. The presence of these features clinches the diagnosis to be Panic Disorder. Also note that the panic attacks are associated with certain situations where his presence is mandatory; these are followed by a severe urge to leave. This points towards a phobic disorder; possibly agoraphobia due to his fear of staying in a common area. Note that agoraphobia cannot be diagnosed yet, as the Diagnostic and Statistical Manual of Mental Disorders-5 (DSM-5) mandates that such symptoms should have been present for 6 months or more. The current treatment guidelines of the American Psychiatric Association (APA) and the American Medical Association (AMA) consider cognitive behaviour therapy (CBT) to be the gold standard treatment of panic disorder. Thus, interoceptive exposure therapy, which artificially simulates a panic attack, should be initiated in this patient. Concomitant pharmacological treatment with a selective serotonin reuptake inhibitor (SSRI) such as Fluoxetine should also be considered. Benzodiazepines (such as alprazolam) are not recommended in these patients, due to tolerance and dependence. While beta blockers were previously considered to provide symptomatic relief in panic attacks, there is a lack clinical evidence on their efficacy; they are probably best avoided.
The Diagnostic and Statistical Manual-5 (DSM-5) defines panic disorder (PD) as an anxiety disorder characterized by recurrent, unexpected panic attacks and persistent concern about future attacks and their consequences, for a period of more than one month. Panic attacks are characterized by a fear of disaster or of losing control, in the absence of real danger. They typically last for 10 to 15 minutes, but can be as short as 1 minute, or as long as several hours; patients may also experience strong physical reactions during this time. PD is extremely common, affecting between 1.6% to 2.2% of the global population; the condition typically strikes during early adulthood, with the majority of patients being affected for the first time between the ages of 25 to 30; a female predilection exists, with twice as many cases as males. Affected individuals are believed to have abnormal sensitivity in their fear networks, resulting in acute fear responses to internal and external stimuli. A deficiency in coordination of the stimuli sent from the brainstem and cortex results in abnormal activation of the amygdala, the center of fear network; this leads to behavioural, autonomic and neuroendocrine stimulation. Furthermore, these patients have decreased levels of GABA-A (which moderates the "flight or fight response" of the amygdala); the low levels of the neuroinhibitor result in increased emotional processing in the brain, resulting a panic attack. PD is known to have multiple etiologies including genetics, substance abuse (such as smoking, caffeine, alcohol and sedatives) and dental and spinal anesthesia. Psychological factors including stressful life events, life transitions, excessive responsibilities, and environmental and thinking patterns are also believed to play a role in the onset of the disease. Panic attacks are usually provoked by exposure to certain stimuli or settings; however unprovoked attacks have also been observed. Note that the first attack is often triggered by physical illness, major stress, or certain medications; patients with post-traumatic stress disorder (PTSD) also have a high tendency for developing PD. Common symptoms of a panic attack include palpitations, dizziness, trembling, dyspnea, hyperventilation and an uncontrollable fear of losing control, going crazy or dying. Other associated symptoms include a sensation of choking, chest pain, numbness, tingling, paralysis, nausea, chills or hot flushes, derealization, and depersonalization. The patients usually have continuous thoughts of impending doom coupled with a strong wish to escape the situation that provoked the attack. The outward symptoms of panic attacks are often associated with negative social experiences such as embarrassment, social stigma and social isolation. Limited symptom attacks, which have fewer symptoms than panic attacks, have also been observed in patients with PD. Current guidelines consider cognitive behaviour therapy (CBT) to be the gold standard treatment; according to multiple randomised control trials, this results in a panic free status in 70% to 90% of patients. The goal of CBT is to reorganize the thinking processes and anxious thoughts regarding the experiences which provoke panic attacks in these individuals. Interoceptive therapy is a component of CBT which allows the patients to experience such attacks in a controlled environment; it has proven to be successful in 87% of individuals. Symptom induction methods in interoceptive therapy, attempt to mimic the most frightening symptoms of a panic attack; these include intentional hyperventilation, breath holding, straw breathing, body tensing, spinning in a chair, or running in place. Panic-focused psychodynamic psychotherapy is another treatment modality of CBT; this focuses on how dependency, separation anxiety and defensive anger plays a role in PD. This involves exploration of stresses followed by probing of psychodynamic conflicts and defence mechanisms in the patient, with the ultimate goal of transference (conversion of an earlier stressor into a non-stressor). Pharmacotherapy can be used to achieve temporary control or reduction of certain symptoms; it is often a useful adjunct to CBT. Note that pharmacotherapy alone is not recommended. Antidepressants such as Selective Serotonin Receptor Inhibitors (SSRIs), are considered the first line pharmacological treatment, due to their anti-anxiety properties secondary to alteration of neurotransmitter configurations. Note that SSRIs may exacerbate symptoms soon after initiation of treatment; they also have the tendency to produce withdrawal symptoms including rebound anxiety and panic attacks, necessitating suitable dosing and education regarding side effects and concordance. Other antidepressants used in these patients include tricyclic antidepressants, monoamine oxidase inhibitors and norepinephrine reuptake inhibitors. The use of Benzodiazepines in PD is controversial, with differing opinions in the medical literature. If used at all, they should be second line drugs, due to the risk of developing dependence and tolerance.