Cardiac reserve

Distinguish among cardiac output, cardiac reserve, and cardiac index... 

Verapamil decreases heart rate, slows atrioventricular (AV) nodal conduction, and produces a negative inotropic effect that may precipitate heart failure in patients with borderline cardiac reserve. Diltiazem decreases AV conduction and heart rate to a lesser extent than verapamil. 

A known side effect of the action of the drug being prominent or problematic because of other disease. As examples, AIDS patients have a propensity to have allergic adverse reactions. Cardiac patients may not tolerate drugs which alter the blood pressure so well since their cardiac reserve is impaired. 

Guanethidine may aggravate congestive heart failure or actually precipitate failure in patients with marginal cardiac reserve, owing to its ability to produce vascular volume expansion, edema, and a reduced effectiveness of sympathetic cardiac stimulation. 

Biondi B, Fazio S, Cuocolo A, Sabatini D, Nicolai E, Lombardi G, Salvatore M, Sacca L. Impaired cardiac reserve and exercise capacity in patients receiving long-... 

Collectively, the human PLN mutant studies indicate that chronic inhibition of either basal SERCA2a activity (PLN-R14Del mutant) or the (3-adrenergic stimulation (PLN-R9C mutant) (Schmitt, et al., 2003) result in heart failure. On the other hand, absence of PLN inhibition by the PLN-L39stop mutant, associated with the lack of cardiac reserve, also results in heart failure (Figure 3). Thus, the identification of these human PLN mutations point to the paramount importance of PLN and its role in maintaining normal calcium homeostatic mechanisms in the human heart. 

The child s estimated blood volume is 80 mL/kg, which is larger than an adult s on a milliliter per kilogram basis. Therefore, small amounts of blood loss can impair perfusion and decrease circulating blood volume. Children have greater cardiac reserves and catecholamine responses compared with adults, allowing them to compensate for fluid losses from hemorrhage, diarrhea, or lack of oral intake. However, shock and cardiopul-... 

Circulatory overload with symptoms of congestive heart failure and pulmonary edema can complicate transfusion in patients with poor cardiac reserve. 

Similarly, verapamil should be used with caution in patients with heart failure, and both diltiazem and nifedipine can cause problems in patients with poor cardiac reserve. However, the PRAISE study (18) suggested that amlodipine may be used safely, even in the presence of severe heart failure optimally treated with diuretics. 

A fall in blood pressure occurs almost always with D-tubocurarine. It is often mild, but may be marked, particularly if a large dose is given rapidly or if the patient is hypovolemic, or has a diminished cardiac reserve or capacity for vasoconstriction (as is not infrequently the case in old age, in diabetes, and in other diseases with sympathetic neuropathy), and is potentiated by other anesthetic agents such as halothane. Myasthenic patients or patients with other neuromuscular pathology are markedly sensitive to non-depolarizing relaxants. 

Moderate aerobic exercise to improve cardiovascular conditioning is beneficial to maintain a slower heart rate, improve cardiac reserve, and maintain skeletal muscle function. Isometric exercise should be avoided. ... 

Edetate disodium, a heavy metal antagonist, is indicated in hypercalcemia (500 mg/kg daily by slow IV infusion) and in digitalis-induced cardiac arrhythmias (15 mg/kg/hour by IV infusion). Ethylenediaminetetraacetic acid (EDTA) will lower serum levels of calcium, magnesium, and zinc. It should not be used in anuria, and renal excretory functions (BUN and creatinine) should be monitored carefully. EDTA should be used cautiously in hypokalemia and in patients with limited cardiac reserve. 

These agents should not be used in edematous states associated with diminished cardiac reserve because any increase in the extracellular fluid volume constitutes a hazard. 

Pindolol (viSKEN, others) is a non-subtype-selective f) receptor antagonist, as described in Table 10-4. Notably, pindolol is a weak partial f) agonist such drugs may be preferred as antihypertensive agents in individuals with diminished cardiac reserve or a propensity for bradycardia. 

The manufacturers say that pioglitazone and rosiglitazone can cause fluid retention, which may exacerbate or precipitate heart failure, particularly in those with limited cardiac reserve. " Because NSAIDs can also cause fluid retention, the manufacturers issue a warning that concurrent use may possibly increase the risk of oedema." ... 

Cardiac reserve volume, 1-6 Cardiac sarcounit, 8-23 Cardiac work and metabolic turn-over rate, 17-7 Cardiopulmonary resuscitation, see CPR... 

---