Sinus Tachycardia in Mitral Insufficiency
Short Summary

43-year-old female with history of continued cigarette smoking and complaints of palpitations. A sinus tachycardia of 160 is documented with little physical activity. Pulmonary function studies revealed obstructive ventilatory defects, consistent with the smoking or beta blockers. She has been documented to have moderate mitral regurgitation, consistent with prior rheumatic disease. At the present time, she is on Inderal.

Patient's Questions
1)    Causes of the inappropriate tachycardia not yet identified. 
2)    Therapy to follow (at present under therapy with beta-blocker Inderal 40 mg 3 tablets daily)
3)    Severity assessment of mitral insufficiency in view of a potential surgical operation
4)    Influence of sport activity, diet and smoking on the clinical situation
5)    Possibility to keep going in for an underwater sport
Medical Background

Age: 43, female

Diagnosis: SINUS TACHYCARDIA IN MITRAL INSUFFICIENCY
Family History:
Father suffering from diabetes and ischaemic cardiopathy; arterial hypertension (mother), thyreopathy (mother).
Patient smoking about 15/20 cigarettes a day
Since 2005 a symptomatology characterized by asthenia, dyspnea and heart palpitation with concomitant finding of sinus tachycardia had began, on the average 100/110 min. up to 160 bpm following very little physical activity. In the spring of 2006 she underwent a diagnostic screening in hospitalization at the Monzino Cardiology Centre; as a result there was no evidence of cardiac pathology. Other possible problems like the hormonal-internistic ones linked to pathologies of suprarenal glands, kidney and thyroid have been ruled out. The patient was discharged under therapy with Inderal 40 mg 1 tablet for three days.
Because of the persisting symptoms, that did not change after the therapy, the patient underwent new cardiological visits and echocardiography. A moderate mitral insufficiency (MI) in fibrotic valve consistent with a history of AAR in childhood, was diagnosed.
The symptomatology appeared, however, odd compared to the extent of the valvular insufficiency that echographically appeared to be moderate; moreover, the constant presence of hypotension to MAP (systolic blood pressure trend always lower than 100 in the 24-hour period) and a slight reduction in the plasmatic cortisol values are suspect of the probable presence of hypocorticosurrenalism so that the patient underwent an endocrinological screening that gave a negative result.
A new transthoracic echocardiography confirmed moderate and unchanged MI, normal cavity dimensions, normal PAP at rest and a transesophageal echocardiography confirmed the transthoracic echocardiography.
Finally, a stress echocardiogram was carried out showing a meaningful increase in systolic PAP: from 26 mmHg at rest up to 50 mmHg after little exertion (50 watt). During this examination the importance of regurgitation was described as modest/severe.  
CASE HISTORY:
02/2006 Italian Auxologic Institute, Milan; ecography of head and neck (thyroid): With diagnosis of thyroid in situ symmetrically developed within normal limits for shape, size, edges and echostructural pattern. Picture worthy of endocrinological assessment
02/2006 Italian Auxologic Institute, Milan; Upper abdominal ecography showing left suprarenal gland of slight increased size and roundish morphology. An in-depth examination with contrast-medium CT scan is required
03/2006 Hospitalization at the Monzino Cardiology Center, Milan with entrance diagnosis: other specified forms of chronic ischaemic cardiopathy and diagnosis at discharge of inappropriate sinus tachycardia.
Examinations performed during hospitalization:
Current therapy Congescor 5mg ¾ tablet for two days
-           ECG
-           CHEST X-RAY
-           TTE
-           ABDOMINAL CT SCAN WITH CONTRAST MEDIUM
-           PAM
-           DYNAMIC ECG (HOLTER MONITORING)
-           HEMATOLOGY, COAGULATION, BIOCHEMICAL EXAMINATIONS, URANALYSIS, IMMUNOMETRY ANALYSES
09/2006 Cardiological visit with electrocardiogram. No clinical and electrocardiographic evidence of cardiopathy.
12/2006 Cardiological visit, echocardiographic and Doppler analyses: Mitral valvulopathy, probably of rheumatic nature.
03/2007 Humanitas Clinical Institute, Milan; Full Doppler mono- and bidimensional transthoracic echocardiogram
05/2007 General Hospital Operating Division of Endocrinology:
Diagnosis at the discharge from day hospital: left suprarenal gland hyperplasia, slight pure hypercholesterolemia, sinus tachycardia and slight mitral insufficiency.
09/2007 Auxologic Institute of Milan: mono-bidimensional Doppler echocardiographic examination
10/2007 Diagnostic Center of Varese, Cardiological visit: it is useful - for diagnostic confirmation of the degree of mitral insufficiency - to carry out a transesophageal echocardiography.
10/2007 Ospedale di Circolo in Varese; Transesophageal echocardiography: Results of rheumatic mitral disease. Confirmation of moderate mitral insufficiency and slight tricuspidal insufficiency.
01/2008 Italian Diagnostic Center, Milan; Pneumological visit: Mitral insufficiency in smoking patient. Respiratory physiopathology, slight obstructive ventilatory alterations of the intermediate airways, more marked in the distal ones due to smoking but also to the beta-blockers dosage.
02/2008 Niguarda Ca’ Granda Hospital, Milan, Cardiological Department; Rheumatic Disease at 5 years resulting in Mitral valvulopathy with recent finding of moderate mitral insufficiency.
During the last two years reported symptomatology characterized by heart palpitations; at the Holter ECG Test evidence of inappropriate sinus tachycardia.
12/2008 Monzino Cardiology Center, Milan; Stress echocardiogram: Maximal test, negative for reduced coronary reserve, with meaningful increase in the pulmonary pressure due to exertion. Test suspended at 50 watt, at the reaching of the theoretical maximum CF, in pharmacological wash out from Inderal (intake suspended 3 days before). 

Expert's Opinion

Unexplained sinus tachycardia is a very frustrating diagnosis for patients and health care providers. It would be important to document the degree of variation in heart rate. This may be available on the Holter. Are there unexplained busts of tachycardia at rest, or it is always with exercise. Such unexplained bursts of tachycardia at rest would suggest an ectopic atrial focus. Does the morphology of the P wave change?
To answer the specific questions:
1. Reassurance is usually the very first consideration. Before initiating beta blockade, as currently prescribed, I would want to be sure that the patient had stopped smoking and was participating in a regular exercise program. The beta blocker would be appropriate if such conservative measures failed. Propranol is an appropriate choice, but may be contributing to a fall in blood pressure. In addition, the presence of any beta blocker may contribute to a sense of fatigue in this young patient.
2. With normal left ventricular geometry, the maintenance of sinus rhythm and the findings of the 12/08 echo, I would not advise mitral valve repair. This should be followed by sequential echocardiograms. If there is any question as to the potential role of surgery, a cardiac MR will help to define mitral valve anatomy and the potential for eccentric regurgitation to the left atrium.
3. There is little question that inactivity and smoking will potentiate all the symptoms of sinus tachycardia. Those individuals who are in excellent physical condition will not have sinus tachycardia but rather a slow heart rate. Smoking will likewise contribute to the symptoms, especially if it is associated with early pulmonary disease. I strongly advise smoking cessation, and would ask that all forms of smoking cessation therapy, including Chantix, be considered.
4. There is no contraindication to underwater sports if the patient is in adequate physical condition. If not, a structured exercise program is advised.

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